In-Depth: The Patek Philippe Ref. 2497, Part 1: Patek’s First Center Seconds Perpetual Calendar
Some collectors like to cover a broad spectrum, and some are completists. When it comes to vintage Patek Philippe, being in the former camp is far easier than the latter. As an illustration of that point, I want to talk about one of Patek’s most iconic and yet – I’d argue – overlooked references: the ref. 2497.
The ref. 2497 was Patek’s first serially produced central-seconds perpetual calendar. Frankly, it’s an oddball design and – dare I say it – not my favorite Patek perpetual calendar. It’s funny now, in hindsight, that I spent so much time on this article, which all started because of one simple question for which there was no easy answer available online. But even I’ll admit there’s something to like about the reference. Any major Patek “first” is worth at least a closer look.
Sitting somewhere between dressy (with a simplified dial) and sporty (with a center seconds and printed minute track), the case is a “virtual carbon copy” (as one auction house has said) of the 2499 – minus the chronograph pushers. However, the center seconds perpetual calendar was also a design that Patek abandoned for 30 years after discontinuing the 2497. In some ways, that adds to the appeal. But even more important are the number of attractive and unique variants – which anecdotally seem to be far more than any other complicated Patek in the era – which not only have achieved notable results on the market but would also make a great cornerstone to any collection.
Between the ref. 2497 and the similar, waterproof ref. 2438/1, only 179 examples were made during a 12-year run from 1951 to 1963 in two standard dial variations and two casemakers (though no Patek extract I’ve seen lists the watches being made after 1959, save one). Of those, 114 were the ref. 2497 and 65 were the ref. 2438/1. That total number is easily found because, unlike any other highly complicated model at the time, production was reserved for a specifically dedicated movement number range, starting at 888’000. The 2497 also coincided with the early run of the longer-lived iconic ref. 2499 – another point in its favor. But, by 1964, both the ref. 2497 and 2438/1 were removed from Patek’s catalogs.
The only known Patek Philippe ref. 2497J with German calendar.
So what makes the ref. 2497 a perfect example of how hard it is to be a “completist” on vintage Patek? Of the 114 made, most were in yellow gold. Rarer examples exist in pink gold (approximately 20), plus three in white gold, and two in platinum, all around 37mm (give and take a few tenths) and around 12-13mm thick. The ref. 2497 was the last of Patek’s “premier” watches, where white metals were used sparingly. With the introduction of the ref. 3448, white metals became a more regular part of production.
By 2024, 55 examples have come to the market. Contemporary prices range from around $150,000 (an outlier) to over $3 million, and currently hover around $350,000 on average. The two white metals command millions and are especially closely held by collectors. There are at least seven more unusual, unique, or important examples you’d likely have to shell out tens of millions of dollars for if you wanted to “catch them all.” But it’s still possible to create an impressive collection.
This entire in-depth story was prompted by my lucky chance to see three of the four case metals together earlier this year in Monaco. Unless you own these three watches (one person does, in fact; my friend Dave, who goes by @theswisscaveau on Instagram), it’s unlikely you’d ever see three metals of ref. 2497 in one place outside a museum.
The collection belonging to Dave, who goes by @theswisscaveau on Instagram.
For the standardized production of the ref. 2497, we can break the watch down two different ways: either by dial design or case manufacturer. Each has a “first” and “second” series. In auction catalogs and dealer listings, people nearly always break down the watch into two series based on dial design. It makes some sense: this is how the ref. 2499 is treated. It’s also the most obvious difference. But this isn’t the 2499, and this treatment neglects the rarity of the subtle differences in the cases. Adding to some confusion, auction houses sometimes say the case manufacturer delineates the series. All of this, plus the three watches I saw, prompted me to search for better answers to a few questions. When did the dial series change? How many of each series were made? These questions, and a few more, seemed to have no answer.
After going through my research (and obsessively cataloging every publically sold piece), I’d argue there are three (or even four) series of 2497. At first, I thought this was a return to an old way of looking at the reference. In Antiquorum catalogs from the 1980s and ’90s, you can see they say (until 2009, even) that there were three series, but they mistook a single unique transitional example as a “second series.” I’m arguing for an entirely different approach and rewriting the scholarship. Maybe it will stick. Maybe I’ll be the guy walking around talking about my imaginary friend, the “third series” reference 2497, for the rest of my life.
When I neared the end of compiling everything I learned, the story ended up being over 5,000 words. Because of that, this is the first of two parts. Part one will cover the practical details of categorizing and understanding the regular production of the reference, including differences in dials, cases, and the ref. 2438/1. Part two will cover rare and unique examples, track the pricing, and look at the legacy of the reference. I’ll warn you now: this is very, very dense. But hopefully, if you’re doing research in the future, this will help you find what you’re looking for.
Two (Main) Dials Of The Ref. 2497
Scholarship on the ref. 2497 was largely right on one thing: there are two main series of regular production dials. These dials are predominantly silver opaline in color, with hands and indices matching the case material made by Stern Frères. Yes, there are outliers, including a champagne-colored dial and some outstanding examples we’ll cover in part two, but generally, a “standard” 2497 will have a white or off-white dial. In addition, only six retailer-signed ref. 2497 are known to have been made (the Gumbiner is the only one to come to auction).
When you look at the early series of ref. 2497, it’s clear the watch draws a lot from the ref. 1526, Patek’s first serially produced perpetual calendar made from 1941 to 1952. The ref. 1526 (almost always) featured small Arabic numerals on the even numbers and small dots on the odds, which meant the dial had a lot of blank space. Powered by the manually-wound Caliber 12”’120Q, the ref. 1526 has the date around the moon phase at six o’clock and sub-seconds in the same location. The singular subdial has a subdivided seconds track, a dividing circle, a track with the date, and another surround. The respective subdial hands reach their appropriate track. Finally, the reference used the very delicate “feuille,” or leaf hands. It’s creative and compact, but that layout looks bottom-heavy.
A Patek ref. 1526 covered in our “Bring A Loupe” column from 2016.
The empty space on the dial – with the Arabic/dot indices – continues to the first series of dials for the 2497. The day of the week and month remain in cutout windows at 12 o’clock. But by moving to center seconds with the Caliber 27SC Q manual movement, the ref. 2497 changed a few things on the dial layout.
Caliber 27SC Q. Photo: courtesy Christie’s
Watches belonging to my friend Dave.
First, with the center seconds, the subdial is simplified to display only the date. Like the 2499, the dials have an incut edge around the subdial and no track surrounding the date. Since the second hand points to the edge of the dial, the track has also been moved there, with a 1/5th-second subdivision printed alongside the printed number for every five-minute interval (minus 30 minutes, which would conflict with the date). That first series 2497 dial also uses feuille hands. The first series of dials appear in movements with serial numbers 888’001 to 888’098, coinciding with the date range of 1951 to 1954.
One other interesting characteristic, shown on the ref. 2497R above, is the occasional plexiglass “cyclops” magnifier that’s (rarely) seen on the ref. 1518 that preceded it. When the 2497G (white gold) sold at Phillips in 2017 (CHF 2.2 million), it also had a magnifier. But the cyclops was gone when it was last sold publicly at Phillips in 2021 (for over CHF 2.8 million). Interestingly enough, the yellow gold and rose gold examples shown together in this story are also the only German calendar ref. 2497s ever produced.
Second Series Dials
The second series dial for the 2497 is actually far rarer than the first (though not necessarily more desirable). This newer, refreshed dial features baton hour markers and dauphine hands – a much bolder and balanced look. But looking closer, there are technically two different sub-types of the second series dial. On the “Mark I” dials, the baton markers are essentially elongated triangles truncated at the ends. The “Mark II” dials are elongated pyramids with sloping points at the top and bottom.
A Patek ref. 2497J with second-series dial, which is the earliest known sale date for a second series dial, October 4, 1957. Photo: courtesy Christie’s
One wrinkle in the scholarship is that second series dials appear in watches Patek lists in extracts as being completed as early as 1955, but research shows that (with two exceptions) all were sold in 1959 or later. Only nine correct second series dials have ever come to auction (five Mark I and four Mark II). It seems like the Mark II dials were possibly left over from the production of the ref. 2438/1 – all of that reference (except one example) featured this dial design. Two of these dials were likely changed out later at client requests because the watches are listed as completed much earlier in 1953/1954. Of course, there are a few other outliers in the ref. 2497 dials, but I’ll cover that in part two of this story.
Mark I dial. Photo: courtesy Christie’s
Mark II dial. Photo: courtesy Chrstie’s
In context, these delayed sales dates make some sense. The refreshed dial of the ref. 2497 was adopted – apparently – due to the then more “modern” tastes of the late 1950s and ’60s. It’s possible (and in some ways proven by research) that examples of the ref. 2497, made as early as 1954, weren’t selling as quickly as tastes changed. Patek looked at their leftover stock and changed the dial design to move their remaining units. This was also the apparent impetus for a late batch of ref. 2438/1, the waterproof sibling to the 2497. Several watches were re-cased by Patek into two-piece waterproof cases with second-series dials. All were ordered around 1960 by Patek from Wenger and Stern Frères.
Not to let my bias get in the way, but I think Patek made a good call with the new design. I’m not a fan of the 1526 or 2497 first-series dials – they don’t seem as cohesive or balanced compared to what I consider the golden era of the brand (like the 2499 and 3448). The second series taps into that later aesthetic. However, they just don’t sell as well on the secondary market.
The success of the second series dial of the 2497 was short-lived. The reference was discontinued a few years later, in 1964. But, in the same way the 1526 dials connected to the 2497, the second series dials overlapped what came next. By 1962, the 3448 was already the anointed successor, with its first-ever automatic perpetual calendar movement. The 3448 and later 3450 (the “red dot,” with leap-year indicator) took the dial’s more modern design language and added sharper, pointed lugs and bolder cases with large bezels for a cohesive design. Speaking of cases…
A Tale Of Two Cases
Like the iconic perpetual calendar chronograph ref. 2499, the ref. 2497 featured the same two casemakers who made cases with similar aesthetics but subtle differences in their execution. The names are iconic: Vichet and Wenger.
A pink gold Vichet-case (long lug) first-series Patek Philippe ref. 2499 that sold at Christie’s in 2012 for CHF 2,547,000. That price seems like a bargain today.
Both cases feature a three-piece construction with snapbacks nearly identical to the 2499 (minus chronograph pushers). And, like with the 2499, one is a bit more iconic than the other. Interestingly, in the mid-2010s, most auction houses didn’t even acknowledge the different casemakers. Luckily, I could extrapolate information from case serial number ranges to address any gaps in records.
I’d make the argument that the true first series of the ref. 2497 has two characteristics: an Arabic numeral dial and a case by Emilie Vichet. Vichet was the legendary casemaker for the ref. 1518 and the early portion of the first series of ref. 2499. Similarly to the ref. 2499, Vichet didn’t make enough cases for the ref. 2497 to span the entirety of the production of the first series of dials. While the number of 2497 cases by Emile Vichet isn’t confirmed, I’ve cataloged every example sold at auctions in the last 30 years (55 different pieces). I feel confident it’s no more than 25 pieces (less than the generally accepted 40-50 estimate you’ll commonly see), all in yellow gold except for two. The production range spans from the start of the reference in 1951 to approximately the end of 1953, spanning movement serial numbers 888’000 to 888,025. There are at least four outliers – in pink and white gold – 888’014, 015, 017, and 018 – made by Wenger, so there may only be 22 Vichet-cased ref. 2497s.
The caseback of a Patek ref. 2497, showing the Vichet casemaker’s stamp at the bottom.
It’s easy to tell Vichet and Wenger cases apart if you can open the watch and see the inside of the caseback, looking for the “Key 9” signature for Vichet or “Key 1” for Wenger. But it’s not often you get to “crack open” a $300,000+ watch. So, like with the ref. 2499, you can start by looking at the lugs very closely.
A “true first” or “first series Vichet” pink gold Patek ref. 2497, aka the “Peter Knoll 2497.” The watch last sold at Sotheby’s in 2023 for CHF 1,497,000.
What I’d call a “third series” or (as known by dial) “second series” Wenger case ref. 2497 in yellow gold sold at Christie’s in 2021 for CHF 250,000.
If you can tell the difference in the case at a glance, you’ve probably been looking at Vichet and Wenger cases more than most or know your ref. 2499 cases. Like with the 2499, early 2497 Vichet cases feature longer “claw-like” that look ever-so-slightly longer, more pointed, and more triangular. These lugs have a steep drop-off that hugs the wrist and wear more modern than their approximately 37mm by 12-13mm case size might suggest. I say approximately because, like the ref. 2499, Vichet cases measure slightly smaller than the later 37mm Wenger cases – something around 36.5mm, whereas you’ll sometimes see Wenger cases measured as large as 37.5mm. The stepped lug is also more apparent in strong examples of the Vichet case, with the “lower” step flaring out a bit more where it meets the mid-case.
In both cases (no pun intended), the bezel of the ref. 2497 has a gently sloping convex shape that ends at the mid-case, which sticks out like a ring that the crown nestles inside. Part of the argument of the aesthetic strength of Vichet cases is that the elongated lugs perfectly match the curvature of the bezel. That might be true, but it’s subtle. The best visual trick of the bezel of the 2497 is that from the front, it actually can look concave and full.
A sloped bezel on a yellow gold Wenger case ref. 2497.
The same sloped bezel on another Wenger case, this time in pink.
Turning the watch over, you can see what is also supposed to be the last tell-tale sign. Often, Vichet cases are described as having a flat caseback, while Wenger cases are “domed.” When you see a truly flat Vichet caseback, it makes sense. You can see an example on the famed Peter Knoll watch with a Vichet case.
A “flat” Vichet caseback.
Some Wenger cases do seem a bit more flat, though not as much as Vichet. While the images below aren’t perfect, you can see that the level of the “domed” shape varies. Then you can also compare to the much flatter Vichet case below.
Wenger case, flatter caseback.
Wenger case, “domed” caseback.
A Vichet case 2497. Photo: courtesy Christie’s
A Wenger case 2497 with more emblematic domed caseback. Photo: courtesy Christie’s
While the ref. 2499 is broken down into four series because of dial variations, the ref. 2497 isn’t so simple. First-series dials can be found across both Vichet and Wenger cases. Since the Vichet case/Arabic dial combination was truly the first, that implies that the second “transitional” series of 2497 should be the combination of a Wenger case/Arabic dial, as seen below. This combination makes up the bulk of production, from movement serial number 888’026 to 888’179 and from 1953 to 1959.
Second Series Cases
The Wenger cases basically look just a little different than Vichet. I covered the key differences above, but the shorter lugs and more sloping/less dramatic drop of the lug from top to bottom is a key giveaway. It’s almost as if the Supreme Court defined Vichet vs. Wenger: “You know it when you see it.” When you see enough of the cases, eventually, it just starts to make sense at a glance.
Doing some simple math, assuming that 25 Vichet cases were made out of a total number of 114 ref. 2497 made total, that leaves 89 Wenger-cased examples ever made. That’s just under 80% of the total production of the reference.
As I alluded to earlier, Wenger cases, largely in yellow gold, seem to have started with movement serial 888’026 (though 026-030 are missing). Before that, Wenger also made a few pink and white gold cases, including the examples here, with movement serials 888’014, 015, 017, and 018. By the 1960s, Vichet was out of business despite being the preferred case manufacturer of Patek, leaving Wenger to make the rest of the cases, including on the ref. 2438/1. The style of the Vichet case also influenced the Chronomètre Contemporain II from Rexhep Rexhepi.
Finally, you have what I’m calling the “third” series of ref. 2497: the Wenger case and second-series dial. By this point, this should be relatively self-explanatory. But as a recap: shorter lugs, a more domed caseback, convex bezel, dauphine hands, and four-facet baton hour markers. But that’s not all for the ref. 2497.
The Other Sibling – The 2438/1
I mentioned before that the 179 total examples of the Caliber 27SC Q movement weren’t solely dedicated to the ref. 2497. In fact, the rare (and I’d argue, maybe more interesting) sibling to the first center-seconds perpetual calendar watch by Patek was one that is nearly identical from all angles except one: the waterproof ref. 2438/1.
A pink ref. 2438/1. Photo: courtesy Christie’s.
Thanks to order sheets from Wenger, we know that 65 confirmed examples of the ref. 2438/1 were made. Fifty of these were made in yellow gold, the rest in pink, all with two-piece cases with screw backs made by Wenger. Almost every example has baton markers (second series, mark II dials), and while some have luminous hands, for the most part, they are all similar to the “third series” ref. 2497. They’re also basically impossible to tell from the ref. 2497 until you flip it over and see the screw-down back. I’ve heard theories that cases were ordered to make the reference after the slowdown in demand for the ref. 2497, and movements and later dials were repurposed into this reference. The watches were made in three batches of serial numbers, from 1954/1955 for the first series and 1959 for the third. The first batch seems to run serial XXX’099 to 110, the second from 135 to possibly 150, and the third from that number to 177, though that still leaves some unknown gaps to complete the total of 65.
A ref. 2438/1 Tiffany seen on a collector in Monaco earlier this year.
The screw-down back of the ref. 2438/1.
The Hölscher ref. 2438/1.
With the waterproof case, the ref. 2438/1 feels like the final evolution of the center seconds QP design for Patek: sporty and elegant. Only 28 have come to market at auction, at about one or two examples a year, and they seem to hold steady in the $300,000 to $400,000 range. There are three ultimate examples, in my opinion. I was lucky to see the first earlier this year in Monaco: a Tiffany-signed ref. 2438/1 in yellow, with HOX stamp on the movement (designating the watch for the American market). There is also a yellow-gold ref. 2438/1 with black dial and luminous dauphine hands signed “Hölscher.” Both are currently in the hands of important Italian collectors. Finally, a personal favorite is pink gold ref. 2438/1 with luminous hands and markers that look incredible.
What Comes Next
For those that stuck with me this far, I appreciate it. And I hope it has proven insightful. At the very least you should be able to tell the ref. 2497 (and ref. 2348/1) series apart. The best is yet to come, however. Maybe something I didn’t emphasize early on is that the ref. 2497 was the platform for what could be considered the largest variety of creative and attractive unique variations ever done in Patek’s heyday. You would be hard-pressed to find a ref. 2499 that matches the thoughtful design of some of the watches you will see in part two.
For the lucky few that are in a position to take all this information and put it into practice to buy a watch, I’ll also take a look at the current state of the market and what to expect for prices. Finally, I’ll have my take on the legacy of the ref. 2497 and its impact on the modern Patek catalog.
Hodinkee
