I have a MK18 that I register as a SBR with the “free tax stamp”. It was approved with conditions. I’ve done some research on selling this item since i’m bored with it now. Some say just removed the stock sell it as it came, some say send letter for removal from registry and sell it. If that is true do I need to wait for confirmation from the ABC boys to sell? Or can I just sell it as it came from the factory since it was a braced gun?