I'd like to share the current state of my research into the Speedmaster 125. I have been researching and analyzing Omega calibre 1040 and 1041 watches and sharing nuggets of that research on my site, calibre1040.com, since last year. I track watches by serial number to gain insight into estimated production by reference and frequency of certain dial features. All of that information is out there on the site if you want a broader understanding, but this thread is focused specifically on the Speedmaster 125. Early on, I was able to quantify the phenomenon that people had noticed nearly 20 years ago: that the Speedmaster 125 is surprisingly accessible for a watch that was supposedly limited to 2,000 pieces now over 40 years ago. I first shared that data here on OF back when I had just over 280 points of data. I now have observed over 730 unique serial numbers, and the data continues to point to Omega making much, much more than 2,000 Speedmaster 125s. I continue to diligently document serials for both calibres, and I see Sp125s at a rate of one for every 4.343 calibre 1040 of any kind. The official production totals from AJTT are 82,200 1040s and 2,000 1041s, so one would expect to see one Sp125 for every 41.1 cal. 1040 watch. The easiest way to project the production total of Speedmaster 125s is to take the total known 1040 production of 82,200 (per AJTT) and divide by that rate of 4.343 to get an estimate of 18,927. And because I am tracking complete serial numbers, I know these are not the same watches being observed over and over again. Yes, there are arguments why the Sp125 might show up for sale, and therefore in my observations, more often than cal. 1040. But there are also arguments why it should show up less often than cal. 1040…I’ve discussed those at length here and here. But to me there is much more to the story than just the production totals. Namely, I have been thinking a lot about the mysterious Alphanumeric Codes. It has long been known that the caseback of the Speedmaster 125 is sometimes seen with a code engraved on the caseback consisting of a letter and a 3 digit number, but it sometimes is not. There are marketing materials from the era that refer to the Speedmaster 125 as being a limited or numbered edition, but the materials I’ve seen never referred to a specific production total or limit. Not any total, 2,000 or otherwise. My data shows that the only Speedmaster 125s that have an alphanumeric engraving have lower (earlier) serial numbers. Watches with codes on the back all have serials beginning with 3507 or 3559, while ones without codes are observed in many other serial batches as high as 4092. It has been suggested that perhaps Omega made 2,000 numbered watches as part of the limited edition, and the rest were unnumbered and unlimited. This would allow for Omega’s official stance to be technically correct while also explaining both why there seem to be so many watches and why many are unnumbered. I want to stress though that my observations do not support that theory. The codes have been observed beginning with every letter from A to L (except J — J might exist I just haven’t seen it yet), and the numbers have been from 001 to 493. See end of post for several examples. I now believe these were numbered series of 500 watches each. This brings us back to production totals. If each letter represents a series of 500 watches, that points to a numbered production of 6,000 (assuming there is a J series). But I cannot come up with a reasonable way in which the alphanumeric codes found on some point to an estimate of 2,000 watches. As for sequential alphanumeric series, there is precedent. The Speedmaster Italy Special Black and Gold DA 145.022, a limited edition for the Italian market back in 1986 was issued in two series, one numbered 1-500 and another A1- A500. (MWO p. 374). The Speedmaster 125 numbered series do appear relatively sequentially. In other words, there is a correlation between serial number and alpha prefix, suggesting that the A series came first, then B, then C, and so on. In addition to the standard lettering on the back of some Sp125s, I’ve observed two alphanumeric codes with the letter I with serifs in a circle, in addition to other Sp125s with a non-serif font for the I series. The circled I is the same symbol, denoting “Italy”, found on the back of the Apollo Soyuz 1975 limited edition was targeted at the Italian market. So in addition to the “standard” lettered series, there was a series of unknown number made for the Italian market. The majority of Speedmaster 125s appear with no code on the caseback. Strangely, the plain casebacks are not all later examples either. My Speedmaster 125, for instance, has no code on the caseback but is one of the lower-numbered serials, and has the earliest manufacture date of any Sp125 Archive Extracts I’ve observed. My caseback could have been added later, but it certainly appears period correct: Omega made the Speedmaster 125 for several years after the company’s 125th anniversary in 1973. I have seen archive extracts as late as late as May 1976. But the fact that I have only observed casebacks with codes on watches with early serials suggests strongly that Omega made several numbered series, perhaps 12 plus one for Italy, and then for some reason stopped numbering the Speedmaster 125 altogether. And they may have been making unnumbered watches all along as mine suggests. As you can tell, I think the “official” stance of 2,000 Speedmaster 125s is flat-out wrong, and not really close. So where did that number come from? I still cannot answer that and I have yet to see any document from the 1970s that states that Omega intended to limit production of the Speedmaster 125 to 2,000 examples. I’ve uncovered some early materials that suggest that it was limited, numbered or commemorative, but none cites what that limit is. Note that the ad above states “Each Speedmaster 125 has an individually engraved number on the back of the case.” Strange then that some of the earliest examples lack the engraved number. I haven’t pinpointed when the number 2,000 first appears in reference to the Speedmaster 125, either. Chuck Maddox wrote his article on the 125 in the year 2000 and alludes to learning about the limited total in the book Omega Designs by Anton Kreuzer (1996), however I have that book and my copy doesn’t mention the production total. But it seems clear from his article that by then the production estimate of 2,000 was somewhat common knowledge among collectors and was essentially considered a settled matter. A Journey Through Time (2007) mentions the total and the Omega Museum mentioned the number 2,000 on Archive Extracts for years, until they made a recent change to eliminate that language. Regardless, I believe that 2,000 is simply an error that commands a re-examining of the archives, page by page if need be. This is where my research stands as of today, but it is an ongoing process and I’m always willing to change my view when confronted with new information. I would like to ask the forum to share any details (serial number, alpha code, photos of box and papers, photos of Archive Extracts, vintage ads, etc.) about their own Speedmaster 125s or cal. 1040s that can either solve or expand the mystery. Feel free to post in this thread or contact me via PM. If you’ve read this far, thank you for your patience. Photos of casebacks borrowed from various places on the web for illustrative purposes.