No need to be jealous, it's a cheap Mac-10, it was a replacement for a two tone one I rattle canned & did a shit job of(it's hiding in my shed somewhere).
Got a new gearbox and an ejection port cover for my M16A3 today, the Orion gear box was working fine but the join in the red wire prevented the motor sitting properly in the grip, I'm sure the rif was working before it was dismantled for posting but I'm damned if I could get the motor sitting properly.
I'm no tech but it looks to me that this gearbox has been worked on, in fact I know it has as I can see through the spring access that teeth have been removed from the gear/s.