Newbie's First Questions RCA TS 721 Restoration

[Notimetolooz]

That HV meter looks OK. I haven't seen that model before. Yeah, it could be the capacitor smoothing effect.

A quick and dirty way to check the audio output circuit is to touch the wiper on the volume control with a screwdriver with a finger touching the blade. Don't have the volume control turned down however. You should hear a hum. If this was a hot chassis set you definitely want it plugged into an isolation transformer to do this.
You would need a FM modulated 4.5MHz audio signal to inject to trace the signal further up (from the volume control towards the tuner).
A oscilloscope could enable you to trace the audio from the tuner toward the volume control.
Without those you are left with checking voltages, resistors and tubes, etc.