This method works wonders on shell cordovan, but is not that good on ordinary calf, but is still likely to improve your damage:
Put shoes on shoe trees and pop a dollop of shoe cream (the soft stuff out of glass jars) onto the damage. Take a metal tea spoon, plonk your thumb into the bowl for added pressure, and slide the back of the spoon (lubricated by the shoe cream) in circular motions across the damage.
Do that for a minute or two. Then wipe off the excessive shoe cream and polish.