waw44 makes a great point. I'd like to see that letter too mmppres. BATF&E FTB will provide a letter after evaluation either way. In the case of big stuff like mortars, there's a much more detailed and complicated display method of deactivating other than cutting the tube up but it's apples and oranges compared to small arms. I imported a Britishicon 3" mortar for a rare mortar section 1943 Ford Canadaicon Universal, (Bren), Carrier that I also imported for a client in 2016. Yes, both the mortar and the UC required a Form 6 import permit as implements of war before I could bring them in.