RCA CTC...Something? poor HV output.

[StellarTV]

That is bizarre. A weak Horizontal Output can cause HV issues, but you'll usually get a picture that won't fill out horizontally. I think it's safe to say your stock HO tube is doing it's job, but those other tubes you have should light up and run too.

And that CRT looks amazing too. You got a good one!

Are you running at full brightness? Will the picture "bloom" (defocus and expand) when the brightness control is fully advanced?