I cleaned the spindle with a Scotch Brite pad and a little bit of Goo Gone. I just turned the spindle by hand and the soot and burnt belt residue came off quite easily. I'm thinking I should probably wipe it down with alcohol before I put a new belt on. Not sure what Goo Gone residue on the spindle would do to the belt. I haven't done anything about the fan yet but it's definitely on my list. I've never replaced one before so it'll be a new experience.
There's no gasket on the opening where the bag connects to the Sanitaire's motor housing but there is one on the bag opening. If that's the original bag from the early '80s, I'm sure the seal is a bit deteriorated. But what the hell, it was never designed to be hypoallergenic, germophobe friendly, sealed environment air filtering device. It's a dust-belching artifact of mid-20th century American industrial technology that cleans the hell out of carpets. It's real good at what it does and not much else, but that's okay. It just is what it is, it makes no apologies and you sorta have to respect that.
The cord hooks came today and I installed one to replace the missing bottom hook. The color is a little off—more of a dove gray than an ivory—but I'm okay with it, especially for the price I paid. I guess at some point, the original top hook will probably break—not that I'm planning to arrange for any unfortunate accidents, mind you—and then the top and bottom hooks will match. While I had the Goo Gone out for the Kirby, I took the Goodwill price tags off the Sanitaire and gave the machine a good wipe-down so not only is the price tag residue gone, the whole machine—especially the motor cover—is nice and shiny.