Regarding the Kirby 'C' Models, does anybody know if there was a Model C and a Model 1C? I've seen references to a Model C and a 1C, and I don't know if there is a difference. I've never actually seen a model plate number with a 1C but I have seen just a 'C' on a model plate. I would assume this would pertain to the 'R' models also.
A Model C is a 1C, and a Model R is a 1R, "in theory." When these models were introduced, they were just called Model C and Model R, then when the next model of each came out the designation 2 was added. So it would have gone C, 2C, 3C 4C etc.