That is a tough one because if it were for personal use I would go back to a time that I could,... of Should of,.... would of,.... bought a bunch of Gov't 1911 .45's when the Military switched to Berettas.
If it were for making a profit, AND person use I think I would go back to a time that you could buy the Thompson "Tommy Gun" without a Class III lisence and a large bank note.