Serial # is 9256XXX. I comprehend it was in the VA law enforcement dept it's complete life and I feel it had been made close to seventy four-75 timeframe. No more engraving or markings from dept, selector marked Protected-semi-vehicle. Hope that helps the database Tony. In the event you stumble https://spencerwtybi.wikiworldstock.com/1082443/not_known_facts_about_colt_combat_unit_rail_gun_45