I had the same problem ID'ing the one I picked up, until I read carefully the article on this site about AC Filters and their history. I have the exact same thing that Denny Graham has: the shape, bolt, and inlet are all alike. It appears that this is actually a
SC-659 model because of the absence of a flange at the bottom of the cover bolt. This was meant for '59 and later models, so I am debating whether or not to use this on my '53 truck, although I guess that the inlet hose would just wraparound the canister a little more (maybe that would give more clearance from the exhaust?) You guys are OUTSTANDING in your knowledge, and I am sure someone knows how well this might work, or if there would be a problem of some kind in this application.
One thing is for sure: the COLORS on this thing will stay original... note my screen name (chomp, chomp)

Anyone have any ideas if the front-side inlet would be a problem for use on a '53 with a 235, mounted in front of the heat riser box? Or if there would be interference from the exhaust?