Russia still has a ton of German military hardware from WW 2. In fact, if you want to buy yourself an authentic StG44 or a G43, the place to go is Russia.
During WW2 we provided tanks to Russia. They went with full kit. Among that kit was Thompson SMGs. Although the Russians liked them, they lacked 45 ammo for them and just warehoused them. A few years ago when I bought my Thompson, the Russians released them and they were imported but without the receiver. So in effect they were full parts kits except for the critical receiver. I got a few of them for parts for my Thompson.
I also got three of the “Russian capture” German Mauser K98k’s that the Russians released from their warehouses.