Avette, I wouldn't expect the chain stores to have much that old, hafta check around the repro dealers, especially ones that have used parts if you can't find a rad shop to make ya one
Jeff, you can just make the cheapie out
here , and
here - the chrome logo button on it just sez GM, and I think they used it on Chevs and GMCs both for at least part of the AD years until the early 60's - the cover on that one [with fan/motor] came from a dealer dumpster in Victoria BC, thrown out as obsolete in the 80's
might be the one you refer to? just a heater core covered with that shroud that contains the fan, but there is one in my stash that's 'boxier' that I haven't really paid much attention to as I have no idea what it's from!
Bill