I found this website but that model wasn't in their database. I contacted them and they were able to start one, after digging up a little more info. They wanted some hi-res photos, so I'm going to send them a few for the page since I finally found my camera.

http://www.radiomuseum.org/r/panasonic_tr_904r.html

they estimate it's from around 1967, which makes it 5 years older than I am