Bruse, get some 4'0 steel wool and polish then up. It should be very safe to use. I'm still shooting some 303 British ammo that is date stamped 1942. If you encounter any problems though, throw the rest out. It wont harm the firearm at all.

Your lucke, as was already said, to acquire a firearm with that provinence. Hang onto it to pass dow to your kids!!