Regarding the used parts hunt:
My Regular / Rectifier had gone bad, charging the battery at 39.5 volts!
I kept riding the bike on single-track (Elec. Start, lights long-gone) with the R/R disconnected from the battery, then charging the battery for a couple hours when I got home. I had been doing this routine since I got the bike last May. Last week I finally found a Regulator / Rectifier on eBay for $20 shipped. You just have to keep searching... sooner or later your parts will turn up.