Sadly, I must disappoint.

From what I've read, scope mounting of the pre WW2 MS was done outside of the Steyr factory. It was 'farmed out' to local guild craftsmen or was simply aftermarket. Some were of the 'Vienna snapper' type, some claw mount. Parts of early MS scope mounts very seldom interchange.

I have absolutely no information regarding the specific Austrian or German shops that crafted and installed the mounts.

My M1910 Takedown wears a Gerard 'B' on claw mounts of unknown origin. It may have been ordered scoped or may have been scoped in England (it has British and Austrian proofs) or in Ceylon where My Grandfather purchased it second hand circa 1931.

It is an interesting coincidence that yours bears the initial 'O.Sch.', the same as Otto Schoenauer.

Otto

Image from 1939 Stoeger of 'Vienna Snapper' mounted scope:

'Original factory mount'? Not at the Steyr factory, as far as I know.

Claw mount on 'Mousie':