Nasa, you mentioned your set not having a UHF tuner.
No UHF. Hey, just call me Naz
It has a click stop for UHF. The little strip on the turret isn't there, though. The tuner has a jack for UHF tunner input.
Interestingly, I had a Zenith from the 50's that had UHF on it.
Did they become standard equipment part way thru 64? Your chassis could be a very early 64 model.
No idea. I'm running with the theory it's a 1964 or 1963 at this point.
Is your CRT the A version? 21FBP22A? IIRC, isn't the 'A' supposed to signify improved brightness and rare earth phosphors?
I'll have to peek behind there and check. It's not a very bright CRT, that's for sure. I'm not sure if that's a function of it being a wasted (It goes through some fun white point shifts as it heats up, and it quite dim the first few min, plus the focus isn't too teribbly sharp), or not being very bright to begin with. I know the set next to it in my room has rare earths, and it's quite a bit brighter.
The earlier non rare earth CRTs - how close to the NTSC standard were they by this point? I know the 15GP22s, etc were supposedly dead on, but were the later non rare earth types also close?