Fake Leslie-style tremolo and chorus effects (it does audibly speed up and slow down when you flick the speed switch, but there's no slow to a halt effect) for the upper- and lower-manual traditional organ voices. The green glow behind the tremolo tabs is not original. I added a remote kick switch for the fast speed switch, and put an indicator light behind the switches to show when it's engaged.
Celeste effects for the different tone generators (a strange tri-phonic detuning and phasing chorus effect. If used in combination with the tremolo it sounds rather like you're going for a ride around on a carousel with a pipe organ in the middle).
(Both the Leslie emulator and the celeste effect do their business by amplitude, frequency, and phase modulating the sound between the different speakers around the cabinet.)
Harmonic couplers for the lower keyboard (blue buttons). The 2⅔′ coupler adds notes an octave and fifth above what you're playing, the 2′ coupler adds notes two octaves above what you're playing, and the 1⅗′ coupler adds notes two octaves and a third above what you're playing. Again, the harmonic couplers only work when only the tab voices are in use, they cancel when any other voices are active.
And upper- or lower-manual percussive instruments (yellow buttons). These are particularly bad at handling any intermittent contacts on the keyboard (you can get multiple triggers of a voice).