Ah, two smarter people than this 'bear of very little brain' have pointed out the obvious that some cars, especially the HJ Vagabond and 52 Kaiser Virginians (not to be confused with other Vagabonds or other Virginians!) are reserialized 51 models, and were part of the process of using up stock, which Kaiser Frazer did so often, from the above models, to all the 1950 cars, to the 51 Frazer, to the 54 Kaiser "Early Special" to the 55s.
Hence, some differences that modern parts places just sometimes don't understand.