I recieved a "generic" 3 ohm reostat from playthings of the past on friday. I contacted them and he said he had none with a switch on the rear. So today I gutted it. After some drilling and soldering, I have a control that will work like the original I hope
Reese you were right about the switch, it does switch on the B+ power according to the diagram.
Check out the pics. the wire in the center is the feed.