I assume you want to replace the cutout that sits on top of the generator? There are voltage
regulators made that replace it, but if I'm correct you still have to use the 3rd brush to
to adjust the charging rate. I have a 12v neg ground one never used, but the charging rate has to be put at only about 10 amps if you are using a 6v generator. terry
There is a fellow in Alberta who posts on VFF who is making them apparently. They are for Model
A's but may also work on later generators. Just do a search for EVR on that forum.
Recently the MTFCA forum announced that Model T voltage regulators have been redesigned using new components and are available for sale. They are working on 8volt and 12 volt versions and are looking into positive ground versions.