This is a very nice example of a WW II production M1A1 Thompson Submachine Gun, manufactured by the Auto Ordnance Corp. in Bridgeport, Connecticut. The M1A1 was introduced in April 1942 as a war-expedient/simplified version of the M1928 Thompson Submachine Gun. This rare SMG is correctly stamped on top of the rear of the receiver with "US PROPERTY". The war-expedient features included the elimination of the barrel cooling fins, Cutt's compensator, adjustable rear sight and removable buttstock. They also employed a side-mounted cocking handle and a fixed firing pin with a slightly longer bolt which allowed the weapon to be manufactured on an easier and more cost effective basis. This example has the standard Lyman "L" type fixed rear sight, horizontal walnut forearm and fixed walnut buttstock. The right side is marked in two lines "AUTO ORDNANCE CORPORATION/BRIDGEPORT CONNECTICUT U.S.A.". The left side is stamped with a very faint "U.S. Ordnance", Cross-Cannon final acceptance proof at the front and rear of the receiver with a "GHD" inspector stamp in the middle. As noted the top of the receiver is stamped "U.S. PROPERTY". The left side of the receiver is marked "THOMPSON SUBMACHINE GUN/CALIBER 45 M1A1/NO. 423447", followed by "S-45". The rear, underside of the trigger guard bow/lower frame group is stamped "664349". The side of the trigger housing is correctly marked "AUTO/SINGLE" and "FIRE/SAFE,". This SMG comes with one 30-round stick magazine and a light green KERR No-Buckle type, canvas sling.