Desperately need help on Raytheion model M-1602

[Bill Cahill]

This is an old project I started years ago, then, it went untoubhed for 18 years.
As it stands now, I've don a complte electrolytic re cap, replaced a number of off value resistors, and, bad tubes.
I get reception with audio, and, picture from cold start.
Vertical is still short, but, stable. I have horizontal discriminator issues.
But, that's not the worst of it.
After it's on a few min. the picture starts getting darker, and, shorter on right hands side.
Then audio volume goes down, and, picture turns negative, and, much darker.
Soon, my raster goes complletely dark, and, sound is very weak.
I removed the high voltage cage today in desperation. I felt the flyback. Core, and, hv donut were warm to the touch. Does this mean the flyback is failing, or, what? If not that, can anyone help me on what's going on here??
No wax has melted yet, but, I'm worried about flyback getting warm, and, the fact that raster completely dies out.
Please help, guys.
Thanks.
Bill Cahill