I made today a quick recording after i modified the Lester K rotary unit with a foot switch for speed control .
https://youtu.be/1FHdjg5A7wEImpuls   
  Please pardon my ignorance.... but why would you need a unit like that extra when you have such a fantastic keyboard that cost so much doesn't it have good rotary sound already?  
Why not ? 
As you know, no musician agrees about how and what a Hammond should sound, even people who have a Hammond are experimenting to match the sound of the enormous Leslie from a mini cabinet, and everything depends on personal taste and experience. You also have a lot of equipment to make your "own" sound, that makes it so fun to be busy with music nowadays.
Regards, 
Soryt   
