a beautiful boat should sail forever.
Sometimes the middle semi circle gets flattened, which when corrected really helps solve whatever problem your trying to correct. In this pic is a vise with the jaws opened just wide enough so the half cylinder middle of the track just fits, and the two flanges are supported by the jaws. Take the peening hammer and set it in the trough, and gently tap with another hammer until trough is round and raised properly. This arrangement also works well to peen out bent flanges.