This is a very nice example of a fairly scarce and desirable WWII SMG as manufactured by the Marlin Firearms company for the United Defense Supply Company, that has been reactivated. This model was design and patented by Carl Swebilius founder of the High Standard Firearms company, who in turn had the Marlin Firearms company actually produce the SMG for the UDS Company. It was designed/developed in 1941 but was not actually produced until 1942, hence the later model number of "UD M.42". They are a very robust weapon being machined entirely out of steel with a heavy driving spring inside the rear receiver, with a front vertical mounted pistol grip with a walnut buttstock and steel buttplate. Originally they were intended as a substitute for the Thompson SMG, however by the time production started, the Thompson/Auto-Ordnance company caught up with their WWII back orders and the anticipated Army contracts never materialized. Its estimated the total production was approximately 15,000, with the majority being sent to the Far East. The are a blow-back operated SMG that used the 20 round Thompson SMG stick magazine. There are two unique features of this weapon, one is that it does have a hold-open catch, that holds the bolt open after the last round is fired. The other is that the right side of the weapon has a sliding cocking handle almost identical to the cocking handle on the FN-FAL rifles. The left side of the receiver has the three-line factory markings followed with "UD M.42", with the full and semi-auto markings on the right side. The receiver is numbered "11736" with the right rear side of the trigger housing/lower receiver area is numbered "UD11535". It has a fixed front sight with a unique fully adjustable (windage and elevation) rear sight that actually sits on top of a shaft that raise out of the rear of the receiver. The left side of the buttstock is stamped "603". This SMG comes with a brown canvas sling but no magazines.