see if you can trade it to some locals for a broom handle german pistol haha. that or a one of the WW2 german machine guns.. worth only about 50k or so.
I doubt they will let that come back unless it goes to the Unit Museum. The stens were Full Auto and there for restricted under the 1934 and 1986 GCA's. But, don't let me stop you from trying, good luck.