In digging around, I read someone reporting a number marked between the lugs, and that made me curious. My Zodiac is still with BWG, but I have pictures, and I was able to read the number between the bottom lugs: 1716613. Does that mean anything? It doesn't seem like a model number--maybe it's a serial number, though I would have expected that on the movement.

It's different from the number inside the case back, which is 773 931. I've always thought of the case-back number as the case code.

The watch is similar to my avatar, but it is marked "Zodiac" in the box where the avatar watch is marked "SST". There is no SST marking on the dial of mine, but it is a high-beat 17-jewel cal. 86 movement.

Rick "curious" Denney

Serial number between the lugs and the case number (model specific) inside the case back.

So, the 773 931 number is the model-specific case number. I'm assuming there are no records as to which case number corresponds to which model, unless it's in one of your catalogs, but then those catalogs seem to have a hole right when my watch would have been offered. I'm thinking my watch, labeled as it is and with a cal. 86 (assuming that's the movement it came with) would have been just late enough to have the high-beat caliber but just a bit too early for Zodiac to have designated watches with that movement as "SST". 1968 is the number that comes to mind--but that is just conjecture. But it would be nice to know if that model-specific case number provided more direct evidence than conjecture.

Rick "surprised that the watches were serialized on the case and not the movement" Denney