Give George over at talonix a try - he may have your knob. You have to use their contact form, but I know they have GE, RCA and some zenith stuff. I got a power switch for my Quasar WITD from them. Lots of off-web stock, I guess. IIRC, knobs are either ES/ET/EP 43 or 49 prefixed parts.
Oh, and GE had a service bulletin on the across-the-line caps. UL requires them to be 400V/dual AC-rated, and GE specified a nice dark blue Paktron film cap. We replaced them by the tons for a while, all free under the service bulletin. One house fire, and the UL got all wanky....
I've got a whole box of those 1000V Elmenco white ceramic bombs. The box is oil soaked, and none of the caps has ever been used or exposed to high temps. Mine are all from Zenith OEM bags. Zenith used them in the boost circuits, and we used Orange drop 1600V replacements.