Not long ago I have found quite a few uppers that happen to be choose offs from rebuilt M16A1 rifles getting offered as "new substitution uppers". Many thanks for using the effort and time to do this. I've quite a few photos from the VN era carbine mag wells if https://jasperxzzxu.wikidirective.com/7072814/the_5_second_trick_for_colt_combat_elite_commander_45_acp