Thats why it warped in the first place. Ive noticed with the scales I've had to restraighten, one of two, or both problems exist. Pivot hole is not straight, or wedge pin has not been sufficiently tightened, allowing the scales to move.
Yours is a challenge . do the holes line up now?
Straighten them and see, if so.. File or sand the scale to match the good one.( had to do that on a few sets, almost all, and open the pin holes slightly as well .