I know an alternator would fix it however I would also think that the 12 volt generator
and regulator from a 56 or later Ford should work as well. Those generators were
nearly the same size as the old 6volts. I would think the armature and field coils
would bolt into the generator housing of a 39 or later flat head. They kept the 12
volt battery up back then (1956 to 60) should do it now.