I've looked into this, and here's what I came up with. First, wether you heat the wheel up to fix it or not, a stress relief (or annealing period) is necessary to remove or re-distribute all the dislocations that were created during the impact. I figure that I'll make a fixture of some sort that would allow me to re-shape the original curves of the wheel by carving hard-wood parts and pressing the wheel on to them, thus requiring much less heating. I know this is very farfetched, but time's on my side =) Feel free to share any ideas you have...