The good news is I found a pretty comprehensive list of codes by doing a search here at VK first.

Bad news EIA 320 doesn't show on any list of codes I've found. Anyone able to point me towards an answer?

Also found this on a paper tag on the rear cover: CB-465. I'm a newbie and I don't know what that means either.

What is the piece of gear that you are referring to?

320 is Trav-Ler Radio of Chicago. They are on the 1961 list but gone by the time the '66 list was published. I wouldn't have guessed them for this set-pretty neat.

Marty, I think this is for the Ambassador console TV he has.

Yes, I'm sorry. It is the Ambassador console of around 1964 vintage. Any clue about CB-465?

I'm not sure if it means much of anything? Could be a part number/label number/cabinet number? Might ring a bell with somebody.

I did find the name behind Ambassador: Allied Stores Marketing Co. I suspect these were sold by smaller department stores around the country as a store brand.