Hi guys, this is quite a niche topic, but I would be appreciative of any help. I originally chanced upon this when looking at the caseback of a watch I have now moved on, this is what it looked like: Thanks to some sages here, I was directed to a website called http://www.vintagewatchstraps.com, which as well as straps, has extensive research on hallmarks (amongst other things, the website is great and well worth a read). This watch was of particular interest, as below the serial number there was a 'Hammer with Handle' mark, containing an improperly struck number of 101 (I believe). This hallmark is known as a "Poinçons de Maître" (PdM). And is best explained by David Bottcher (the owner of vintagewatchstraps) here: "In the 1920s a formal registration system was introduced for Swiss watch case makers, to provide traceability for watch cases made of precious metals back to the actual maker. This required all precious metal watch cases made in Switzerland to carry a mark to identify the case maker. In Swiss the mark is called the Poinçon de Maître, which is literally the "Punch of the Master". This is referred to in English as a Collective Responsibility Mark, but I rather like the Swiss term so I will stick to using that. Watch manufacturers didn't usually want the name of the case maker appearing in the back of their watches because the case maker was normally a separate company that supplied many different watch manufacturers with cases. To comply with the Swiss law a system of marks and code numbers was devised by the watch case manufacturers, with different symbols representing the different case making regions of Switzerland, principally Geneva and the Neuchatel and Jura regions. The marks are called collective responsibility marks because each one was used by more than one member of the association. These marks are usually seen in gold, platinum or palladium cases. Although provision was made by the Swiss watch case makers association for silver cases to be marked, these are rarely seen. The lists of marks and registrants were centralised in 1934 and the only information the Swiss authorities now have is from that date. However, the 1934 lists have lots of gaps in the sequences of numbers. This is because in the decade between the lists first being drawn up in the 1920s and when they were centralised in 1934 there were a lot of changes. This is particularly so for the mark of a hammer with handle" He goes on "The hammer with handle mark is rather interesting because there are only two numbers listed in the 1934 list, 115 and 160. This seems to imply that there must have been a large number of companies with this mark at one time, but that they had all gone out of business before 1934. It seems unlikely that such a large number of companies would have gone out of business in 10 years and therefore I suspect that something else happened, but I don't know what. An official description of the meaning and use of each of the marks that was supplied to me in 2011 by USH-APIC contains no reference to ... the hammer with handle. Unfortunately this description is not dated. The one thing that can be said for sure is that if your watch has a hammer with handle mark and the number on the hammer head is not either 115 or 160 then it must have been made between when the Poinçon de Maître system began, circa 1925, and 1934. I asked USH-APIC and the Swiss Central Office for Precious Metal Control about this, but they have no records prior to 1934. If the numbers were issued consecutively starting with 1, like for the other marks, there may have been up to 180 companies, and possibly more, using the hammer with handle mark registered with the Cantonal Authorities outside Geneva in the mid 1920s when the Poinçon de Maître registration system was introduced." I therefore sent David the picture of my watch, which I included above. We agreed it would be worthwhile having a look to see if there are any other gold omegas of this period with a similar mark. It is here where I turn to the collections of Omegaforum members, if you could post any gold watches with the 'hammer with handle' mark, it would be greatly helpful. I have been actively looking on eBay for gold watches of this period, which has so far turned up a single result, with an unfortunatley rubbed hallmark: Thanks for reading this if you have got this far! Lucas
And if you want to read the PdM information from the website itself, it is here: http://www.vintagewatchstraps.com/swisspdm.php#pdm2
This might help too http://omega-constellation-collectors.blogspot.com/2007/09/history-of-gold-in-watchmaking.html Invaluable source of information: Thanks, Desmond! W