Assuming its all original,
You need to use a 6volt starter because of the number of teeth on the flywheel, but it can be run on 12 volts. The generator, fuel sender, heater motor, and light bulbs won't like it though...
Any 6 volt foot starter from 37-54 car or truck could be used. If you want a solinoid starter, look for one from a 49-54 car.
Plenty of salvage yards in MN, A new set of brushes and its good as new (usually).
3spd of 4spd?
A factory shop manual would be a good investment...