Doc, a 12V, or 6V starter will work just fine for you. If you find a good one, I'd check the brushes, commentator, bearings and field, clean it up and use it. In fact, the 6v starter will turn faster and, as long as you don't abuse it, it'll last for a long, long time. My buddy's got a '51 Dodge that he converted to 12v, 10 years ago. It has the original 6V starter and it has never missed a lick.