My grandparents had the yellow convertible in reply G. They gave it to me at a young age. I don't remember what happened to it. Do you know what the model number is?
This was a common problem that didn't allow the paper bag to inflate. I have seen this several times when customer assembled. Hoover later added a sheet to instructions showing right and wrong assembly.
In bold text at the end of the description, the model is listed as U4037; that's immediately followed by Service Merchandise's identifier, so it's hard to detect.
I was reading the post here and started to go through the photos posted from catalogs. The photo #12 in the post features a commercial vacuum that I bought in 1977. I bought it at a J. C. Penney store locally. The machine was marked as a GE Premier Commercial. I owned it until the late 1980's when I traded it for my Kirby 560. It had very good suction and easy to handle while cleaning. Sometimes I have had regrets about trading it in.