Just remembered, one of mt Thomas organs, the Celebrity Royale had 2 61 not keybeds, a 32 note radial arced pedal board AND in between the keybeds...a Arpeggio/Glissando strip...worked superb. All you had to do is hold a chord and run your thumb across the bar (it had 61 little rollers) OR just flip the switch and run your thumb across for full Gliss.
You could change chords on the fly, use sustain pedal etc.

You could vary the speed, go slow/fast it was so cool!