MTR
8918
Update
Today I was called by the shop.
Their managing director has now personally inspected the watch. It is said to be really just a "touch" of a scratch that is "completely superficial" and would be removed with a quick very very light polish for one second (without losing any material).
The manager assured me that "100% even under a magnifying glass" you wouldn't see anything (the bezel of this watch wouldn't do with polishing either without showing it).
I have decided to just trust him now and will go back to the Omega Boutique tomorrow. If I also have the impression that the problem is solved, I will buy the watch.
Anyway, I'll keep you posted!
Best
Thomas