I foresee much work with washing up liquid and a brush, followed by much sand paper use.
While the electric fire element probably works sort of OK, a nice new modern ESC would work better. Probably something like a Marine Viper 25, and use a NiMH battery of whatever voltage it says on the motor label. When built, it probably had a lead battery. These were far from ideal, but back then the only game in town. Much better alternatives are available today. Anything modern to plug into the radio will need the wiring pins shuffled to work with the Sanwa radio.
I had a bit of a google, and found this - "the positive is one of the outside wire, the neg is the center wire and the signal is the other outside." The standard that all known modern gear comes with is that the outside wire (i.e. the one that goes nearest the edge of the radio board) is ground (batt -ve) and black. The center wire is +5 volts, red, the inboard wire is the control signal, and white. So basically, on a modern ESC or servo, winkle out the red and black pins from the plug, and fit them back into each others hole in the plug. The plug might need a bit of attention from a craft knife if it has a polarising tab.
Keep posting questions, you will get up to your 10 soon.