This will give you more than you ever wanted to know about the various members of the Anschutz family involvement in German gunmaking, but very little with respect to Germania.
The little I know is that Germania Waffenwerk did not survive the war, and the modern Anschutz business was created in 1950. The Germania Waffenwerk name can be found on handguns (usually target guns), rifles and SxS shotguns. They also supplied .22 training rifles to the Wehrmacht. Some firearms were produced in house, but many were acquired from individual gunmakers in the trade.
Without seeing the proof marks, I would suspect this rifle dates from just before or just after WWI. Much later and it would almost certainly would have been built in 6.5x57 which was a much better solution for a Mauser action and gained popularity between the wars.
Their production and sales must have been pretty extensive, because they pop up at gun shows in the US fairly regularly. I have seen examples of each of the above. No doubt most were "liberated" by GIs during the war.
Sadly, because of the extensive bombing and post war looting of Suhl and Zella-Mehlis, we know very little about many of the pre-war gunmakers.