Congrats!
I don't do repairs, however do have an extensive convertible collection. That red switch is probably the original switch, and they do fail.You never know when the last "click" will be it's last. Yours was manufactured between 1960-1962. The cord looks original as well with the original Hoover embossed plug. The colors were Clover pink and pearl white. That is a replacement bag, the original would've been of vinyl in the color to match the hood. The original took C type bags, but yours might take Hoover A type or Eureka F&G. They're really good carpet cleaners. You mentioned "refurbished", do you know who did it? Since Hoover was made in Ohio for years, hopefully you can find a switch at a local vac shop, I doubt they still make them but not sure. There are some wonderfully informed Hoover collectors on this site who will know way more than I do, hope you get it up and running!