My father has two thompson commandos and was told by a dea agent that he had to pay the tax on it because they can easily be converted to full auto by taking the firing pin out and putting them back in backwards. Is this true? Also the dea agent told him that theres a dea type of weapons permit that my father can get that will allow him to carry full auto weapons at anytime and not pay the tax when he purchases these nfa weapons. This sounds a bit absurd. Comments?