Dead 16GP4

[bandersen]

I have an unmarked 16" metal bell CRT with a "Z" painted on it. I'm pretty sure it's a 16GP4 just going by the dimensions.

I tested it with my Sencore CR70 and have absolutely 0 emissions. I suspect there's either an internal break in the cathode or it's completely worn out.

I then tried every trick I know of:

Touched up the base pins with a soldering iron - no effect
Pulled off the base to look for a break inside - nope
Rejuvination - no effect
Auto-restore - no effect
Even tried to reweld the cathode from every angle with no luck.

Anyone have anymore ideas ?