I have bought a slightly beat up Elmarit 90mm some years ago on vacation in New York. The serial number indicates it's from 1968.
It has a poorly done engraving on it saying"GP-23".
I wonder what could that mean?
Is that some kind of secret photographer code, the initials of a famous artist who lost his mind drinking too much absynth?
Or just an inventory number following GP-22 (whatever that was)?