I really should have mentioned that. I couldn't get the remember what buttons I pressed thing to stick in the script so I just blanked all the organ 'stops' and you have to press them each time you start the organ to get sound.
The two bottom interface buttons are the far left keys, simulating pedals. The left side is the lower two octaves of the basic keyboard and the right side is all the upper octaves of the basic keyboard. I was hoping that splitting the keyboard would make it more usable.
Its not ideal, but otherwise I was getting the buttons showing up as pressed but still not making any sound, which was even worse. Basically I went with buttons instead of keyswitches to make it easier to layer sounds.
Thanks for trying out the instruments and the kind words, Nigel.