Thanks Peter, I popped over to eGun and had a closer look. I wonder if the 3-digit numbers are maybe just a partial serial, used to help keep parts together during assembly? Weihrauch did a similar thing for many years. Some of my older HW 50's and 55's have a 5 or 6-digit serial, but only the last 3 or 4 digits appear on the breech block and locking lever.It might be interesting to see if there are other numbers elsewhere on the gun.
I confess to ignorance of German gun law in early post-war days, but I have the impression that serial numbers were more of a manufacturer's preference thing than a legal requirement then.Per my last note, Weihrauch HW 55M no. 140385 (1963) has the full number on both receiver sections, but only "0385" on the bottom of the breech block, and face of the barrel-lock bar. I have others like this...but also older ones with the full serial in all locations.My only Dianas with individual serial are model 60 match rifles. The sporting models 5, 27, 35, and 50's covering from the 50's to the 80's have no serials, though starting in the 60's they have date stamps.All my Walthers and FWB's from the 1960's have full serials.And as for for what BSF was up to...?!?!, LOL.
I doubt there's any chance of getting info on BSF serial #'s as they were bought up by Weihrauch nearly 20 years ago; rather unlikely the records would have been preserved in an accessible fashion.Don R.