I have to say I don't remember seeing one. The stock is folded up almost to the magazine, the magazine is either .45ACP or 9mm, and it's just a cheap stamped weapon. The ports in the barrel lead me to think it would be a .45. they tend to climb faster than an F-22 in an auto mode.

Here's a similar idea, not the same weapon.

http://world.guns.ru/smg/dk/madsen-m46-m50-m53-e.html

Or maybe this:The Carl Gustav M45 is a series of Swedish blowback operated, automatic sub-machine-guns first produced in 1945 and adopted as the standard weapon of the Swedish Armed Forces, and also sold to Egypt, Indonesia and Ireland. The guns are chambered for the 9 mm Parabellum cartridge and have a rate of fire of 600 rounds-per-minute with a muzzle velocity of 365 meters-per-second and an effective range of 200 meters. The original M45 took a Suomi 50-round box magazine, the B variant (Carl Gustav M45B) introduced in 1948 changed the magazine for a double-stack magazine with a capacity of 36-rounds which proved so reliable it has been widely copied in other weapons. The C variant has a bayonet lug and the E variant is selective single-shot or automatic. A silenced variant was also made and used by US Special Forces in South-East Asia.
http://www.probertencyclopaedia.com/browse/FMC.HTM