Use the original pellet feed arm, and a toothpick/bbq skewer as axle pin.
The whole thing (body + arm) can be mirrored in your slicing software, so you can have it either as a left or right hand side pellet loader!
Thanks to Art&FlyWork for the original PP750 design!
The author remixed this model.
I changed the body slightly to fit the Umarex Notos, which is based off of the PP750.