...
...the current plan is to wait for a response from the frame builder, Steve Rex. If he has some kind of genius fix that involves a reinforcement at the botom of the crack area, I'll pay him to do that. If not, drill a couple of relief holes, carefully fit a new seat post, then build it to rideable condition. At that point, I'll try to fit a front derailleur and run a cable under the BB, first trying out the run as under there and through the formed groove in the stay brace.

If that seems iffy, I'll probably install one of those plastic thingies on the underside of the BB shell and see how that works out.

I do think I'll probably paint tit, but not until I'm convinced I like riding it enough to warrant the effort. It looks like an easy white to match, so I can pretty much touch up the bad spots in the meantime. I guess it's a product off one of the guys who got out of frame making, and did not make and sell enough of them to leave much in the way of a history. It does seem to me to be very well constructed. Like a labor of love.

Paint looks original to me.