Am I understanding this correctly, that you can't find brushed rings in your size? But that you can find polished in your size?
Uh, you have a running car, and a pair of jack stands, and some steel wool. Make 'em brushed. All you can find is brushed? Get a polisher and some compound: Same deal.
In other words, if you can find rings in your size, you have what you need. Maybe I'm misunderstanding the issue.
And this is the first mention of 6.5" rallies I've ever seen. I have a full set in the basement, never could figure out what they were originally off of. I got them off a Ramcharger 20 years ago.