Here we have the schematic for a Farfisa Compact Duo combo organ. Back before there were websites, cameras and photographs and such, companies used to draw out these little lines and stuff to tell you how their stuff worked. Sometimes the guys that built the organs read these to learn how to build them.
You’ll probably need the F/AR schematic too.
Don’t be stupid and hurt yourself if you are going to work on your organ. You really should find a tech to work on your gear. That way he can do what he does, and you can do what you do.