Anyone Rebuilt an Original Style Vacuum Advance

Sounds like you have a Prestolite distributor in there, with cast iron body and unscrewable end cap/vacuum nipple on the vacuum advance pod. These weren't meant to be rebuilt any more than the ones with non-removable end caps were; you'll note the two metal halves are crimped together. Your options are a new one without removable end cap or a NOS original-type replacement. I am fairly sure I have a NOS complete Prestolite distributor for that engine (w/vacuum advance); is yours single-point or dual-point?