Are there any sources for watch backs? Why are they so difficult
You might want to try Otto Frei. There was a third brother who ended
up with a *vast* inventory of watch repair stuff, but hasn't ever
done anything to market it. So last I saw, (about a year ago), it
was all just sitting there in the warehouse. I'm sure there are
backs in there. There may not be any more recent than about 1980 or
so, but it's worth a shot.
You probably want to talk to John or Steve (Frei) about it, it's not
anything the normal phone people would know much about.