1980 RCA Colortrak 25" troubleshooting help

[groovy]

I am hoping to get some input from any of the RCA tech's on this site to help troubleshoot my set (hopefully a retired RCA tech). This TV an oldie but a goodie.

Here are the specs on the set:

1980 RCA colortrak Model GD936TR
XL Chassis CTC-101B

Manufactured Sept. 1979, I purchased brand new December 27, 1979

It has only ever had two repair jobs both in the 1980's. The flyback transformer was replaced and the chroma IC was replaced - both performed by an authorized RCA repair shop.

I will preface by saying that I do have the full schematic on this set and am familiar with the schematic.
I am a novice but have repaired many electronic things as far as replacing capacitors, resistors, diodes, transistors - my de-soldering and soldering skills are excellent, I can read a schematic and understand a fair bit. I do not have a scope for tracing, I do have a good meter for testing.

This set has been in constant daily use since new. The wood cabinet is like new and I like this set and do not want a flat screen TV. I intend to fix whatever is wrong with this set. That said, here are my issues:

The picture is otherwise excellent. I have adjusted the screen, color driver and bias controls as per schematic and the result is a beautiful picture.
However, (here are my issues), occasionally the picture flashes bright white with visible re-trace lines, then it is gone. This is random and often happens when the video signal is a darker scene or a change in scene. The other issue is the picture flickers a reddish hue (not fully saturated, just a step up in hue), this is a quick flicker and then it returns to a normal picture - now, this issue occurs more frequently and it is getting more frequent - this happens on both color and black and white pictures.

The tuner is not really used as the signal comes in through channel 3 via provider box. The CRT is excellent, I suspect the issue to be in the video circuitry or a varying cap in the power supply (????)

I was hoping to find someone who may be able to point me in the right direction to starting troubleshooting as to capacitors, IC, transistors or resistors to zero in on. Hopefully a repair tech has seen these conditions before on this chassis model and knows the fix.

Thanks for all who can help me!