Just checked Ebay- - - - -there are at least a dozen Delco original-equipment 12 volt regulators listed as "aircraft" equipment for prices from $30.00 to $50.00 each. They will also work in automotive applications, just as well as the $250.00 "refurbished" ones that are also there. I'm probably going to buy a few of them just to have them on hand. With a quick bead blast and paint job of the cover with gloss black enamel, I could flip them for a $100.00+ profit, assuming I wanted to do that (which I don't!)
Jerry