The important thing to remember is that certain portions of a gun cannot be "restored." They can only be cosmetically refreshed.
A punky stock head can be restored, generally after the outside has been refinished, by saturating the fibers with thin cyanoacrylate or very thin epoxy. Properly applied, the liquids will wick along the grain and reconsolidate the wood fibers. This process will often give you a stock head that is stronger than the original wood, but requires that the oil has been removed first.
