The final wartime revision of the Thompson Submachine Gun, the M1A1 replaced the articulated firing pin in the bolt with a fixed pin on the bolt face, which by that point had become the de-facto standard for SMG bolt design. The barrel is blued and fitted with an Auto-Ordnance/Thompson marked Cutts compensator, but properly lacks cooling fins, and the parkerized receiver is marked "U.S./PROPERTY" behind the fixed peep sight with faint inspection marks on the left side near the breech. The trigger housing is unnumbered, with a parkerized finish and proper selector/safety switches. Fitted with a grooved horizontal forearm, pistol grip, and a fixed buttstock with a smooth steel buttplate and "B.A.-J.L." arsenal marks stamped on the left side. Three extra stick magazines are included. Provenance: The Allan Cors Collection