This is a beautiful example of an exceptional Auto Ordnance Thompson 1921/1928 US Navy over stamp submachine gun. This specific submachine gun was originally produced in the 1921 configuration and was later over stamped with "U.S. NAVY MODEL OF 1928" then subsequently sold to the Harrisburg Police Department as documented on page 103 in the book "The Thompson Submachine Gun" by Roger Cox. This model came into being because of the lagging sales for the 1921 series of SMG and the fact that the USMC successfully used many of these New SMGs in Nicaragua, Auto-Ordnance began to remark their inventory with the intent of peaking sales interest to various police and government agencies. The basic difference between the original 1921 and 1928 configurations is that the latter has a slightly reduced cyclic rate of fire. These Thompson SMGs were probably one of the best machined and hand fitted submachine guns ever produced. They have a distinctive deep rich blued metal finish with the bolt remaining in the white and excellent deep dark brown walnut foregrip, pistol grip, and buttstock. If you ever have a chance to disassemble one of these weapons, you will be amazed at how well they were made, the parts just slide together like glass. This specific weapon still has all the traditional and distinctive Thompson features that are so easily recognizable in the gangster movies and were used throughout WWII, such as; the Auto-Ordnance ported compensator on the end of the barrel, the short 10 1/2 inch barrel with cooling fins, the vertical pistol grip, the detachable buttstock, and the fully adjustable Thompson ladder rear sight that is graduated from 100-600 yards. The left side of the receiver is marked "U.S. NAVY/MODEL OF 1921" with the 1928 dated over stamped on the 1921, with the serial number 6167 below the marking block. Farther back on the left side of the receiver it is marked "THOMPSON SUBMACHINE GUN/CALIBRE .45 AUTOMATIC COLT CARTRIDGE/MANUFACTURED BY COLT'S PATENT FIRE ARMS MFG. CO./HARTFORD, CONN. U.S.A." The right side is marked with the five lines of dates along with the two line 'AUTO-ORDNANCE CORPORATION,/NEW YORK U.S.A". The top of the receiver and is marked with the Thompson "Indian Arrow" head logo. This Thompson is fitted with one 20-round stick magazine and includes a modern made FBI style carrying case that has compartments for the weapon, magazines and accessories.