Unusual K98 "OO" Receiver Code?

[NYBushBro]

I picked up an old K98 sporter that had an arsenal code "OO" on the receiver ring that I haven't been able to locate any information about. The date stamp on the receiver is 44.

Anybody know anything about this code... as I haven't been able to find anything on the internet about this.

[Combat Diver]

I can't find any thing on a "OO" or "00". Can you post a picture?


CD