"Bear" markings on a K98k

[BigMo]

I was looking at a dot 45 K98k today. (sorry no pics) And it seemed like a put-to-gether rifle. It was a dot 45 receiver, serial #422, with dot marked stock and handguard, and later features. What was odd? about it was that it had a small "bear" marked on the barrel, receiver and bolt. The bear was clearly marked at the same time- same size etc. The serial number on the bolt matched but appeared to have been milled off and then restamped to match. It looked like me to be the "Berliner" bear. Any guesses?
Secondly that late in the war, did they use Mauser marked stamped trigger guards?
It had no import marks and I was wondering about that bear............

[kcw]

A left side profile of a standing bear? The stamp of the W. German proofhouse @ Berlin from 1953 and later? A "put together" from spare/surplus parts would have been required to be submitted for proof.
During the couple of years directly after the war Guild makers often did custom work for GI's without benefit of official "proof" but as the years went on things tightened up governmentally speaking. I suppose it's possible that sometime after 53' somebody had access to a supply of NOS 98k parts and had a guild outfit put it together, which subsequently submitted it for the required proof.
Or maybe (and more likely?) the W. Germans were selling off some 98k's that they'd allowed to retained for police services ,etc.; and the government required the weapons to be civilian "proofed" prior to the material being released, just as the Brits did with surplused military arms in the late 50's - early 60's?
Any WWII military final acceptance markings on it?