Would look at the cost of a replacement wheel before looking at repairing that. My LBS just replaces that sort of wheel as the part cost more (when workshop time taken into consideration) than a new wheel, suspect it will be similar for your LBS.

If you really want to repair it, the only real source for generic wheel parts is Wheels Manufacturing, all good LBS's should stock/be able to get their parts, if they (WM) have any that it is another matter.