This is an Ithaca Model 37 riot gun with trench handguard attachment and "USSF" stamped on the lower left side of the receiver. The left side of the barrel is roll-stamped with the two-line Ithaca legend followed by "CYL" and a "P" proofmark, with a second "P" stamped on the left side of the receiver near the barrel. The barrel is fitted with a WWII pattern six-hole heat shield with the bayonet adapter, that is fitted with sling swivels on the and on the buttstock. The Ithaca "Roto-Forged" logos are stamped on the right side of the barrel and receiver. The barrel and receiver have a gray, parkerized, finish. The stock and forearm are walnut with a military oil finish. The stock pistol grip and wrist have impressed checkering. The black plastic buttplate has impressed checkering and the Ithaca logo in the center. The serial number, "371369484" is stamped on the lower right side of the receiver above the trigger guard, with "USSF" is stamped on the lower left side of the receiver. The right side of the bayonet adapter is stamped with "SP-30-06" . The significance of these markings is unknown. A nearly identical Ithaca Model 37 trench gun is illustrated on page 267 of "THE WORLDS FIGHTING SHOTGUNS" by Thomas F. Swearengen with the caption: "Right side of an Ithaca Model 37 reportedly made for Army Special Forces". We make no guarantee as to the authenticity of all of the aforementioned markings.