I've started poking around inside the set.
The 5U4 has an odd looking base. It looks fried but one side tests fair and the other good.
The flyback looks OK physically.
Well there's one source of trouble. A HV lead has broken of the rectifier tube.
Time to let that CRT cook for a while at 7 VAC.
After 30 minutes, it was just reaching green. After an hour, it was well into the green
I repeated the tests with my Sencore CR70 at 6.3 VAC. It takes a good 10 minutes to warm up, but once it does the emission and life test are decent.
I won't consider using the rejuvinate function until I get the set running and evaluate the picture it produces.