This is a desirable example of a British Contract Colt Government Model semi-automatic pistol with the "W" prefix serial number. Towards the end of WWI the British ordering office was issued Contract No. "U.S. 6755-MM264" for 5,000 Colt 1911 Government model pistols, with this specific pistol being shipped as "1 of 300" in Feb 1918 to the British Air Service/Royal Air Force. The slide is marked "COLT AUTOMATIC/CALIBRE .455" with the left side marked with the two-line, two-block patent and address slide markings with the Rampant Colt behind the slide serrations. The frame is marked on the right side "GOVERNMENT MODEL" over the "W 91645" serial number. The left side of the frame and upper area of the trigger guard bow are marked with single "broad arrow proof" over the British "Crossed Pennant" proofmark, with a British "Crown/G6/F" proofmark applied at Colt by the final British inspector with the Colt "VP" Verified Proof directly below that. It has an early Colt blued barrel with a polished chamber areas that is stamped with only a "P O" on the underside in front of the barrel lug. The barrel is not stamped with the "455" caliber designation; however, a 455 auto cartridge fits inside the chamber. This fine example has the early checkered slide stop, the early type two checkered thumb safety with the flat mainspring housing, short grip safety, wide Colt hammer with the checkered spur and the checkered walnut grip panels. It has the correct British contract half-tone magazine with a lanyard loop on the bottom that is marked "CAL.455 ELEY".