I made the 8 pin din adaptor cable to work with my XK-1. It allows you to control the vent from the organ along with carrying the audio signal. One of the pins is a 'Leslie sensing' pin that is connected to ground. So, all it needs to fool the organ into thinking it's hooked up to a Leslie is the ground signal jumped to that pin. I would imangine that if the SK has the same pin signal connections as the XK-1, then the wiring diagram from the XK-3 Yahoo group site should work for it as well.
Kurzweil PC3, Hammond SK-1 + Ventilator, Korg Triton. 2 JBL Eon 510's.