So, I recently acquired 2 gearboxes as payment for working on another gun. However, I can't figure out what type of gearbox it is. It looks like a version 2 in the back, but a version 3 everywhere else. It doesn't use a full motor cage like the version threes either. If you look at the place the motor enters the gearbox, there are some weird lines there too. Those almost seem like a channel for the wires to run through. Can anyone help identify this? I'm going to salvage as many parts as I can (gears, springs,...), but I'd like to know exactly what type of gearbox/what gun it goes to. They were bought on ebay as Classic Army version 2's, but I know that they are not CA's, and are not Version 2's.
Pictures: