So while I'm waiting on parts for my next stab on the rotor output contacts, I took a stab at the tooling that I will need to sand the output contacts flush to the output contact plate.

The idea is to use a sheet of glass with sand paper glued to it and use the rig to keep the contact plate parallel to the surface of the glass. The three corner screws can be used to  adjust the parallelism. The shaft that the contact plate is mounted to will be free to float up and down in drill bushing pressed into the plastic frame. The spring between the pressure knob and the frame will allow the frame to keep the contact plate parallel to the glass when just pushing down on the knob and moving it around on the sand paper. I think it will work.