Joe, I have a similar problem.
To move a model 66, I cut the wire that left the motor. As I recall there was a wire that went from the motor to the wall, and then the (metal off market) controller foot plugged into a three-prong outlet on the right side of the sewing machine.
I am trying to figure out how to re-wire the machine so it all goes through the controller foot or simply to add a new wire to the wall outlet.
This machine did not have the controller foot mounted inside the cabinet with a knee lever.
Any advice or parts sources, or links diagrams to view are appreciated.
This is a working woman repair, as there's no help around the house here.
Lisa