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", this particular Thompson was sold to the New Hampshire State Police at Concord, New Hampshire, at an unknown date. Blade front sight on the Cutts compensator and a folding Lyman rear sight, showing the signature cooling fins on the barrel, horizontal forearm, rear pistol grip, and a quick-detachable hardwood buttstock. 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 separate selector ("FULL/AUTO" and "SINGLE") and safety ("FIRE" and "SAFE") levers. The item is equipped to accept both drum magazines (one Auto-Ordnance "Type L" 50-round included) and stick magazines (four 20-round blued magazines included). Also included are a number of related papers, brass cleaning rod, a tan canvas transport case, and a tan canvas drum magazine pouch.

Excellent, with 97% plus of the original blue finish, showing mild edge wear, areas of gray and brown patina, and minor spotting and handling marks The wood is also excellent, with mild dings and scuffs. The accessories are in good order. 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 478.