Year on this Zenith?

[mwplefty]

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