Tom posted about this before. You have pretty good control over bending the rim if you unbuild it and straighten just the rim. Use a compass to draw a circle on a perfectly flat surface, then gently bend this way and that way until it's as good as you can get it. A few pieces of wood will help you focus the force, brace the part that doesn't need to be bent, and so on.

Worst case scenario: your rim is toast. What have you got to lose*?



*Ekfept your two front teeff? Seriously, you don't want to bend it far enough to fatigue the metal; but I don't think that's a risk.