If there are any sharp bends in the rim it seems unlikely that you'll ever get nice smooth braking from it so probably best to replace it. I'd do the same thing that I do when I wear out the brake track and need to replace a rim. Tape the new rim alongside the old with two or three pieces of tape and then transfer the spokes over one at a time from the old rim to the new one. This preserves the position of the spokes in the hub where the spoke heads have already settled into small grooves thereby minimizing stress on the spokes.