Hi,
There is no way of reapairing a skin as such, but have a suggestion for a patch up.
Use vascaline or some kind of petroleum based moisturiser on the outside of the skin to soften it. Then take it off and use some 'Duct' tape over the actual crack.
Thus the skin should be back to decent condition to stop it cracking again, and the tape covering the crack will be on the inside.
Hope this helps??
Lest, October 2008