Imperial/Crumar Road Racer Electric Piano

[neddyboy]

I have an Imperial electric piano, early '70s, designed by Gary Hurst but built by Crumar. It looks like a modified Road Racer. Two keys on the bass end of the keyboard aren't working. The main circuit board has little daughter boards for each key, but I checked them out and they seem okay. The contacts work too. After that I'm lost. Can anyone point me in the right direction? I suspect this is a common problem on old Italian keyboards.