Just started restoring my sickly Opus 3, replacing all gunged up sliders and switches. But now the modulation section is not working at all

So if anyone can help me track down a service manual or schematic I may be able to get down to making some serious prog again

Oh also, does anyone know where to get a replacement key from, I have one white key that has snapped, must have been the jamming in of the carving knives!
Cheers
Dean UK