If you CAREFULLY remove the back of the set the chassis number should be printed on a sticker on the back of the HV cage. The chassis number is generally the easiest identifier to look up found on Zenith TVs.
If it is a Round screen color set then it is generally more desirable to collectors.
If you live near Milwaukee or Chicago you might be able to sell it to me....I got a bit of a soft spot for that brand(seeing as how about 10 Zeniths have found their way to me).
A search of sam's yields the schematic info for it and a (tiny, grainy) picture which don't tell me what it is exactly.
https://www.samswebsite.com/en/photo...index/id/14706