Model C common?
I have seen several for sale lately, so I would say yes. This model is a 1950 I believe, so its life could have lasted into the sixties or seventies for a very thrifty and careful owner. It has good suction, great tools and does a good job. Adequate as someone recently told me, for the requirements of the time. Of course, it cant hold a candle to yours! Congratulations on your new Rainbow! Its a great machine.