Update!
Got it insured, titled, and registered. Historic plates too!
After towing it down to MVD and back, I tried the broken off fitting again, and it came out! Yahoo!
Installed the petcock and bolted everything back together and took it out. It runs warmer now without the heaters, and it got hot going down the highway. The guys that deal with these say to check the vacuum advance, and if it's okay, I have the water distribution tube to face...
It's okay at lower speed, so I'll be able to make the shows this weekend.
Just have the stoplight switch to install when it gets here tomorrow.