I have one of these I need to do the same on. At some point in its history, someone simply snipped off the line that went to the lamp and just put a bit of electrical tape over the exposed cord stump. The power cord and foot pedal cord both have some scary looking splices and change colors a couple times. I opened up the junction box on the motor and it looks terrifying, one of the wire joins was just left naked!! I don't know how anybody used it in this condition; I'm afraid to plug it in to even test the motor. I took it off completely for now...I wish it had a spoked handwheel so I could make it a hand crank easily, the machine itself glides beautifully. I'm told it was working until it was put away but I'm not sure I believe that!
I might bring it to my cousin next time I'm out his direction - he's an electrical engineer and works on terrifying stuff for a living so this will be peanuts to him!
I found a replacement spotlight lamp on eBay I'd like to put on it too; it's missing the lens cover part but better than nothing.