I have the feeling that I have fallen here in pity. And I understand the criticism, though it seems unfair to me.

But how about a joint project?

I know how to implement it, which means how to make the bezels very precisely.

But I've reached a point where I miss the last percent of input.

 

Once again, thank you for joining a discussion about my original question.

How do I know? I don't know. No proof. If I had a proof for my statements, I would be an OMEGA god. Even Bienne doesn't know more than most of us here in this forum. They even managed to create this facetted case for the Trilogy LE (which I know apart from all other 'slight little changes' was not by intention).

The production can be focussed on 1958. Most of the 2915-1 and 2915-2 were produced in this year, apart from a very small range of 15.49X.XXX/15.50X.XXX examples in 1957 and 16.648.XXX examples that were produced in 1959.

The method of 'engraving' is clear to me. Those bezels were etched. It was and still is the only way to create these contures with accuracy.

Would be interesting to know if they etched the finished bezel rings or made them out of etched metal plates. I have some 2998 case backs, missing the inner -X stamp and also the outer sea horse etching. And the 'SPEEDMASTER' etching on the caseback of the 2915 could also only be made after the part itself was finished. So maybe the bezels were etched after the actual ring was finished?

Interesting, but (maybe?) not really important.