Hi,
You answered most of the pertinents already, but few people remember that Gulf Oil distributed paper models of the Lunar Lander and the Service modules of the Appollo program, and based on that I would believe that your radio is going to date from right about the same time, 1969/1970. Without any other solid advertising materials at hand with anything specific I cannot add anything more than that. You might find some references and prices if you can find an ad in an old Popular Mechanix, or Popular Science Magazine from that era of the US space program.
:I'm trying to find out about a radio I picked up at a flea market. It has "Constellation" on the front and a sticker on the bottom that mentions 'Gulf Tire and Supply Company". Prehaps this radio was distributed by the company? The radio is an AM desk model with a white plastic case. Any info would be appreciated.
:Thanks!