Hey this looks familiar. I am working on a KRA59A for / with my little brother, and am having to do the same thing.
What box is it on? Do you have the numbers on the old slides? I might be able to cross reference to a newer part number.
As for straightening the old ones. Depends on what tools you have available. I used a large arbor press. I found a piece of solid steel stock that fit between the rails on the U portion of the runner (small U) to solve bend in the vertical plane. That way I wasn't pressing on the bearing surface of the runner.
When bending them I used a 3 point bending technique, where the slide was supported by pieces of wood dowels at the extreme ends and then applied the force from the ram very slowly. Go slow and be patient. It is a pain to do, but you can get them back in working order. Be careful and try to avoid using pliers or other pieces that may mar the bearings surfaces of the slides. That can cause exaggerated wear on the female or mating portion of the drawer runner.
One tip I found is to first straighten the vertical bend (causes drawer to sag when pulled out, your second picture) then fix the side to side bend (your first picture). Go a little at a time and alternate between the two, check against a straight edge often.
