The rostyles have been looking a bit sorry for themselves. While the spray-can job I did a few years back was fine, I omitted to treat the rust I couldn't remove (duh!), so now that has come back to bite me.
Rather than buy a stack of cans and spend a few days stripping and spraying each wheel I decided to get them done properly. So I sought out a local company which would take the wheels, give them a blast to clear off the old paint and rust, then powdercoat them. Romax in Stockton did this in a day, and I think even they were surprised how well they came out! I chose to get them done in silver, so I could paint in the black myself, but for now I'm happy with just having the plain wheels and think I'll live with them like this for a while.