Thanks, I just found the Zenith Oracle, & it says the chassis is 5524, from 1938. The stickers on a couple tubes say 1955, so I figured it was at least that old, but 1938 kinda surprised me.
Oh, the serial # is R327262, & here's the link to the oracle,
http://www.oldradios.com/reference/zenith.htm EDIT: I see now you were spot on, my stamp on the chassis is slightly dirty. This chassis was used in 5 models of radios, 5J196, 5J217, 5J247, 5J255, & 5J353.