Stauffer, Son & Co., Stauffer & Co. and IWCWatches stamped with the marks "SS&Co." or "S&Co." are often described as being made by IWC. If the mark is SS&Co. this is certainly incorrect. If the mark is S&Co., the watch or the movement could have been made by IWC, but it also might not, so it is best to be careful.
Stauffer, Son Co. (SS&Co.) were watch manufacturers established in 1830 with a factory in La Chaux-de-Fonds, the French speaking watch making centre of Switzerland. Movements made by Stauffer, Son & Co. are often marked with a trademark of their Atlas factory in La Chaux-de-Fonds of "SSCo." below three small triangles, although they did also use other (earlier) trademarks. Later on this mark was also used on some movements supplied to Stauffer by other manufatcurers such as Fontainemelon.
IWC were, and still are, are a separate company in Schaffhausen, over 200km away to the North-East in the German speaking part of Switzerland.
Stauffer, Son & Co. had a London subsidiary called Stauffer & Co. (S&Co.) who imported watches from the parent company in Switzerland and distributed them to the huge market of the British Empire. When the demand for watches became greater than the Atlas factory could fulfil, Stauffer & Co. in London sourced watches and movements from a number of other manufacturers, including IWC, which is where the link to IWC comes in.
Movements supplied to Stauffer & Co. London by factories other than their own Swiss factory were marked with the Stauffer London trademark of "S&Co." under a crown in an oval cameo, and the Stauffer trademark "Peerless", or sometimes with the SS&Co under three triangles mark.
IWC movements supplied to Stauffer Co. in London were always marked with the trademark S&Co. under a crown in an oval, but so were movements from other manufacturers suc as Eterna, so finding this trademark or the word Peerless on a movement does not guarantee that it was made by IWC.
Certain IWC calibres, such as the cal. 64 used in all of IWC's first wristwatches, are well known and easily recognised. The only way to verify that a movement was made by IWC is to look at references of IWC calibres.
IWC supplied Stauffer & Co. with complete watches, and also with bare movements which Stauffer had fitted with dials, hand and cases. The only way to verify that a watch with an IWC movement was supplied to Stauffer & Co. as a complete watch rather than a bare movement is to ask IWC. If the watch was suppled complete they will, for a hefty fee, send you an "extract from the archives". If it was supplied as a bare movement, IWC will not supply an extract from the archives.
I hope you have found this guide useful. If you have, please register a vote for it. If you haven't found it useful, or have noticed a mistake, please let me know. Thanks!
Regards - David