The mag release button experienced a horizontal line sample on it, as opposed to the circular line sample observed on the current kinds, see the image under for an illustration: Sadly, I am on journey so I am unable to article photos from the bolt. It really is MPC engraved. https://garrettjvsro.wikigiogio.com/1088721/the_smart_trick_of_colt_combat_elite_commander_45_acp_that_no_one_is_discussing