This is a highly desirable early production U.S. military contract, Colt Model 1911 semi-automatic pistol with the early slide markings, nitre blue finish, early parts with the rare and very desirable early small serial number markings. This early pistol was manufactured in the first full month of production, being assembled on 25 January 1912. It was shipped to the Commanding Officer of Springfield Armory on Feb 3, 1912 in a shipment of 200 pistols. The pistol has the lustrous high polish Colt commercial blue finish with the nitre blue finish on the thumb safety, slide stop, hammer, trigger, mainspring cap and barrel bushing. The high polish finish was replaced by the military "dull finish" blue at approximately serial number 2,400 on April 24, 1912. The slide is marked with the early two-line, two-block Colt factory address and patent dates and circled Rampant Colt along with "MODEL OF 1911. U.S.ARMY" on the left and right of the slide respectively. The right side of the frame ahead of the trigger guard is stamped with the very early and highly desirable small serial number markings of "No. 137", the left side stamped with the early small size "UNITED STATES PROPERTY", and the circled "WPG" monogram of Ordnance Inspector Walter G. Penfield above the magazine release. It is fitted with a blade front sight that has been filed to a patridge style blade and round top notch rear sight, checkered wide hammer, checkered slide stop, thumb safety, and magazine catch, short grip safety, smooth mainspring housing, lanyard loop, diamond pattern checkered grips, and a correct pattern exposed floorplate two-tone magazine with lanyard loop on the bottom. The barrel is high polish on the tube and brush blued on the rear portion. There is a "question mark" style stamp visible on the bottom ahead of the lug, writer is not familiar with the aforementioned marking being used in this manner other than as a factory rework mark, or possibly replacement.