Originally manufactured by Colt as a Model 1921 Thompson SMG, one of a number stuck in inventory due to sluggish sales; while today the Thompson is recognized as an American classic and one of the all-time finest "heavy metal" SMGs, at the time it was a novel, untested and expensive weapon, and few were willing to roll the dice. The U.S. Marine Corps was an early adopter, and the firm attempted to capitalize on the connection by adding "U.S. NAVY" markings to their 1921s, updating the features based on USMC feedback, and overstamping the "1921" to "1928" to match their newer model. According to Herigstad's "Colt Thompson Submachine Gun Serial Numbers and Histories" (page 751), this particular Thompson was shipped to the Sheriff's Office of Beaver County, Pennsylvania at an unrecorded date, as part of a seven piece order. The item is also recorded in the inventory of dealer Mike Free of North Huntingdon, Pennsylvania in 2000. Blade front sight on the unmarked Cutts-style compensator and a folding Lyman rear sight, showing the signature cooling fins on the barrel, dual pistol grips and quick-detachable buttstock with a small "anchor" on the front. The left side of the receiver has the aforementioned "U.S. NAVY" model markings ahead of the 5-line address and caliber markings, with the Thompson "bullet" logo on top and the Auto-Ordnance address and 6-line patent markings on the right. The trigger group is numbered to match the receiver on the underside, with knurled selector ("FULL/AUTO" and "SINGLE") and safety ("FIRE" and "SAFE") levers. The internals are of the 1928 pattern, with the reduced spring and spring guide and correspondingly heavier bolt assembly, with brass Blish Lock and felt padded oiler. Included with the lot are two 50-round "L" drum magazines, four 20-round stick magazines, a cleaning rod, and a black leatherette transport case.

Excellent, with 90% plus original blue finish, showing some high edge wear, minor spotting and light handling marks overall. The wood is fine, with some hairline cracks around the stock iron and mild scuffs and dents overall. The case is fair. Mechanically excellent. NOTE: This weapon is a National Firearms Act (NFA), fully transferable Class 3, which is registered with the Bureau of Alcohol, Tobacco, Firearms and Explosives, (BATFE) that is classified as a "Curios or Relic" as defined in 27 CFR, 478.11. These weapons are still subject to the provisions of 18 U.S.C. Chapter 44 and 27 CFR part 479.