This is an excellent example of an original Union Switch & Signal Model 1911A1 pistol which is made from the factory with no serial number. The post plausible explanation why these exist was that these were sample pistols used when it was necessary to have examples of production pistols for educational or other purposes. The left side of the slide is marked with the "USS" followed by "U.S. & S. CO. / SWISSVALE, PA. U.S.A." and the right side of the frame is marked "UNITED STATES PROPERTY M 1911 A1 U.S. ARMY". The barrel is marked with the letter "G" ahead of the lug and "L" marked blue contract magazine. Muzzle plug does not exhibit later milling marks and barrel lug does not exhibit typical contract marks. The pistol has the Dulite finish with blue trigger and fitted with the correct Keyes Fibre grips and a lanyard ring on the heel. The small parts are checkered except for the slide stop which remains smooth. See page 264 of the book "U.S. Military Automatic Pistols", Volume II, by Edward S. Meadows.