Sorry I wasn't clearer with my explanation Funken! I'm on overload right now with work and blah..blah...blah. Everyone's busy.
The left inside dial controls the tuner on the B835R and the other, early 8-tubies like it (Zenith produced several; mine is a Y832). The larger knob on the left-front is the band selector, while the right knob and backing-dial work together for the power/volume function. Again, the center knob is for tone, and it's effective.
Be careful polishing the dial face and pointer; the gold finish is VERY thin and wipes off easily. If it isn't perfect, just clean it and leave it alone. I haven't perfected a painting technique for these yet (time, again...) but someone needs to. This is a weak spot on most of these radios.
I pulled mine off the shelf and gave it a try today. Sounds great! Not as punchy and dramatic as the later (plastic face) 845 variants, but a damn fine sounding radio nonetheless. Mine hasn't been re-capped, so I need to put it aside until I can do that. There's only about 25 radios in front of it...sigh....
Enjoy yours Funken!