For Foot Switch #1 and 2, you can use most any foot switch that is normally closed (or one with a polarity switch) that has a 1/4 inch mono plug. The operating system does not have a software switch for polarity like some keyboards have. If you can find one, there is a four switch foot controller SZ-FC2 that can be plugged into the Foot Controller position in the back.
I don't remember, though, if rotary on/off is one of the things that can be controlled with a foot switch. I believe rotary fast/slow can be controlled for the drawbar organ.
If you or someone you know can work with wiring stuff, there is a schematic of the wiring needed for building a FC-2 foot switch about mid way through the article at
http://www.home.no/gunnar-jonny/bobs/Hruby.htm