So...what I did seems to work but is a little challenging....keep in mind there are 2 guys playing 4 boards.
Here's what I did:
Part 1, keyboard 1, right hand split is a B3 emulation that is the backend
Part 2 , Keyboard 1, left hand split, is the initial melody with no harmony
Part 3 and 4, Keyboard 2 (yes you could do them all on 1 with 3 splits, are a combination of part 2 and a harmony part.
Sounds in use:
P1: Air Tech Organ, 588700000, slow leslie
P2: Air Tech Organ, 677740034, slow Leslie and Studio One Presence Far Fisa layered
P3 and P4: uses p2 settings, uses Cthulhu vst to create harmony using layer of Studio one Presence VST's: Saw synth, Three Horns, and Far Fisa.
I'd upload a sample but neither a 36sec mp3 nor a 1.4Mb zip will upload...beats me...