My research on this forum points to http://www.rim-repair.com
as the place I would try. I have no direct repair experiences to relate, just a quote of $150/rim + refinishing. For a bad bend, it's $200. If the bend is on the inside, then you can probably skip the refinishing; otherwise, it's a pretty hefty charge to unbend+refinish. For minor out-of-roundness, they recommended leaving it. That's what I've done, moving the bent wheels to the rear where it can't damage critical steering components. My research couldn't seem to find any one shop where people are completely happy ... there always seem to unhappy campers relating their horror stories about rim repair shops.