Hello Scott
I believe the Amorada song you heard was played live by Mark Whale on the Wersi Scala Organ using OAS 6, and saved using the Midi Record function, (Same as hard disc recording but using Midi instead of Audio) now as all Wersi OAS instruments use the same sound samples, when it was played back on my Abacus (Running OAS 6) it would sound the same, (Which is why all Wersi instruments come with the same Midi demo files installed) to play it exactly as you here it live on the Abacus, you would need to use the right hand multi split and add a pedal board.
All the presets and styles used in the demo are factory standard.
You are quite correct about Amorada being popular with organists, in particular Hammond players, as Latin tunes seem to fit in with the organ sounds perfectly.
One tune that has been done to death though is Tico Tico, (Originally played on Hammond by Ethel Smith) which in the 80s, organists used to use, to see who could play it the fastest.
Hope this answers a few questions.

Bill