I collect WW I and WW II Military Items. Looking at my collection of Machine Gun Magazines, I came across what I thought was a Sten Magazine. What I have is an unknown SMG Magazine. It is 9 5/8 " H 2 1/4 " W 1/2 " thick Mag stop is 6 " from top of Mag. Holds about 18 rds. of 9 MM Ammo. I think it is inserted thru the pistol grip. I would like help identifying this Magazine. ] Pat Mc Laughlin