If they won't make it a primary then it can always be a secondary unlock (which is what I will be rigging this for), although I'm not sure if I'll be submitting this. And yeah, this is heavily based on the Sten.
I want to add a moving bolt on the right side a la the sniper's SMG, but I don't know if it will be worth it (won't be very noticeable from first person). I was also planning on taping two mags together for a reload similar to BF2's AK-101 (same two mags used over and over), but it seems silly now. Oh well, still lookin' bad.