Try connecting the chassis to the B- and see if there's any change.
You can make a form of signal tracer out of a small amplifier. Even an old battery pocket radio.
Kind of running out of ideas, as the job is not in front of me.

Well ok but if it's a dead short I'll have fireworks all over, lol. I already tried a cap between chassis and b- and b+ and made no change. I have several 9 volt radios but don't have an idea how to use it as a sig tracer.

I find cheap powered computer speakers make a great signal tracer. just use a small cap. (like .047 uf 600 volts) in series with the computer speakers input and probe around the audio circuit.