Year on this Zenith?
 

I know we've discussed this set numerous times before, but we've never pinpointed an exact manufacturing date (or close approximation). The seller says approx. 1972, but I just bought a very similar (nearly identical) set that I was told was from 1976 (they are even both 19"). I can't check mine because the tag on the back of the set fell off. I'm going by what I was told when I bought it.

http://cgi.ebay.com/ZENITH-COLOR-TV-...3#ht_702wt_907

I'm sure that's a '72 model ("C" line). This is a four tube hybrid set and the last Zenith tube sets were produced in '75 ("F" line). If the date tag is missing on your set, it is easy to date the model year by the chassis number. "A" line = 1970, "B" line is '71, "C" line is '72, "D" line is '73, "E" line is '74, "F" line is '75, "G" line is '76, "H" is '77, "J" is '78, "K" is '79, and "L" is 1980. 25EC58 would be an "E" line from '74, 25KC45 is a "K" line '79 model.

nut beat me to it...

Yep, 1972 would be correct and may have the 19CC19 chassis, which has a series string tube line up. Had this set in the house growing up but with a different UHF knob that made it easy to spin.

I'm going to post additional information about my set soon. I have yet to take off the back and look for the chassis number.

On Zenith TV's of the mid '70's through the '80's, there is usually a date sticker stuck somewhere on the chassis or on the cabinet.