Wally,
I refurbished my Harrison heater and blower motor based on a process outlined by Deve and I'm quite satisfied with the results. The heater has a 12V blower motor and a DC motor contoller with a potentiometer that gives me infinite fan speed control as opposed to high/low. Here's a link or two for your reading pleasure:
Heater Restore12V UpgradeLet me know if you have any questions, good luck!