Definitely not m10. Also, macs usually have a stop tab to prevent the mag from being jammed up to far into the action. Not saying it ISN'T m11, but I'd have to see a side-by-side comparison first.
Is it zytel? I suspect a ghetto blaster, like a tec. Possibly m11 380 too.
Good luck, very interesting.
Right turn, Clyde.