Double Naught Spy,
According to what has been revealed so far, the gun was brought here, legally, just as any other weapon or war trophy that was captured, and was made legal by the US Government. There is a big difference in the legality here between truly stolen, and what our own government made US property, by saying someone could legally keep an item, and claim ownership. There are too many cases of this that are too numerous to mention here. I know of several in my neighborhood.
If it was indeed, truly stolen, which would be that it was brought to the US, without the governments knowledge, then I am all for returning it. However, from everything I've read, that is not the case. As soon as our government signed off on it, they declared that weapon as someone's legal property. That is then on the back of the US Government, and not ours.
There is a big difference in stolen gold and paintings, and weapons of war. How may weapons has every country seized during a conflict, and either used, kept, or destroyed? What I'm looking at, is this backfiring on any of us who may own war relics, or own historical items that were made legal by our own government, and we citizens being left holding the bag.