http://www.woodyswheelworks.com/index.shtml
I haven't had to use them myself, but have heard good things about them on ADVrider.com
Up till May of this year, I lived a whopping 1 mile from their shop and helped a number of new riders out by pulling wheels and housing bikes while Woody and his guys did their work. This was usually fixing spoked rims, and it wasn't cheaper than buying something used, but his wheels were FAR superior to anything OEM. No idea on pricing for fixing mag wheels, and it may be cost prohibitive, but you'll be hard pressed to find a more ethical, or skilled, wheel shop to call and talk with.