Copied from another post I made on this watch:
It may be a decent watch for all I know, but it has nothing to do with Zenith. When I asked the seller on what he based his claim that this was a "Favre-Leuba by Zenith", he responded that Favre-Leuba was to Zenith as Tudor is to Rolex. Complete rot; there was no such interconnection. Just a brief marketing relationship whereby Zenith added "Favre-Leuba" to the dials (along with "Zenith") of a few watches, most notably cal 135s, that it permitted F-L to market. Possibly the seller assumes that because the founder of Zenith was Georges Favre-Jacot, he must also have founded Favre-Leuba. Nope. Favre-Leuba was founded well before Georges Favre-Jacot came along, and he had nothing to do with the company.