There is a local shop in my area that does Alternator, generator, starter and water pump rebuilds for shops all over the U.S. Last time I talked to the guy he stated they send out about 40 rebuilt alternators a week. they have been in business for years and really know their stuff. I don't know if it is possible but if you want to go this directions I can send you their contact information and they could possibly rebuild and convert your 6v starter to a 12v starter using the existing pinion gear, avoiding a needed change of the fly wheel.
