Fusil,
Does the gun have the forearm with it? If not, that is a fairly common situation. The Germans were required to turn in their weapons, on penalty of death, for destruction.
Some people removed the forearms and telescopes in an effort of resistance. GIs often removed attractive guns from the piles as War Trophies, some were missing these parts. If the forearm is missing, it is possible to have it replaced. If you remove the barrels and post a clear photo of all the markings underneath them on the barrel flats, we can provide more information. From the marks that can be seen, the gun was proofed after the 1939 proof law came into effect.
Mike