Gerber Sabre 408 - 404 Retrofit

I am looking for two things.  I am retrofitting a Gerber 408 and I want to keep the main board in place and just replace the processor board.  The main board has all of the connectors to the servos,encoders, limit switches and also very simple interface buffering, level shifting 7400 series integrated circuits and the like. I am trying to keep this board in place and only change the board that sits on top by designing a custom printed circuit board that interface with the existing main board thereby simplifying the retrofit. 

The two things that I am looking for are:
1) any overall schematics for the entire router or any of the circuit boards.
2) I could use a main board in working or non-working condition so that I can reverse engineer the traces.  I would do partial disassembly so the board would be rendered un-usable. If any one has a board that they are willing to give up, please let me know.  I can pay for all shipping, etc.