Hoover and Eureka
Your Hoover 475 was the mid-range model of the 1935-36 lineup. The top of the line model was the 825 and the economy model was the 300. Although the bag is genuine Hoover, it is not the original one for that model, the original would have been black with orange lettering.
Can't say for sure about the Eureka, but I'm thinking it was made in the late 20's to early 30's.
You didn't say whether or not they run or how well they run, but even if you did I couldn't put a value on them, as that can only be determined by what someone is actually willing to pay you for them.
Hope this helps,
Jeff