Honestly, it looks alright to me. An automatic luger is cash money.
Though keep in mind to size the ejection port with the rounds you're using (not sure what kind of a caliber it is), and I'd give the front grip a bit more of an angle.
Oh and the metal bit infront of the muzzle, doesnt sit too well with me, but that's just a nitpick :v

Thanks for your comments.
As i usually do, the base of this drawing is a kitbashing:
C96 for handle, trigger and gunstock.
lugger for the "knee mechanism"
PPS-43 for the barrel.
The metal bit infront of the muzzle comes from the soviet submachinegun.
The spent cartridge are ejected upward (as in the luger), but a removable deflector deviate it either right or left to make it a Ambidex weapon. I'm not shure if this would work correctely........
I will make a try with a bit more of an angle for the front grip .

Yeah, the aesthetic is there, but as to the ejection... yeah, I'd check into that for accuracy. That's about the only gripes I have at this point.

Good work here! Glad to see this thread alive... Waritem: You should go on with guns, since the y-39 must be the one of the nicest AU guns so far