For this Topre restoration I bought a 91NEO0100 from yahoo auctions.
It looked good until I looked under the hood
Cleaned the case
Disassemble the plate from the PCB. It seems there was some soda damage? there is no corrosion though.
Cleaned the PCB and the Rubber. For good measure the stabilizers are lubed and the sliders are lubed. I left the plate for how it is for now. I will later sand it down and repaint it.
assembled and nice :).