I wouldn't have a problem with doing that, because its steel. I might even do it with alu. But it will never be straight/round. That might anger you.
Bend it back with the cresent wrench, check for flatness on a flat table,counter,etc. You could make it more flat via a BFH. (big _ucking hammer)
Yeah, a vice would probably be a better way to do it. The larger gripping surface would make it a lot easier to avoid little zigzag bends all over the place. Just be sure to use some sort of pad on the jaws, or you'll wind up with pockmarks all over your ring.
(And what's all this about "gentle, considerate, loving violence"? Um... )
if you have a nice smooth area (such as a concrete garage floor) and a car or truck or something, try running it over, no not a burn out on it, but just slowly drive over it, sometimes if the metal isn't bent to badly, you can sort of press it back into place, not a garenteed fix, but it sure is lazzzzzy, and that's always good. ooooh yeah, what a *****in run on sentance!