if the crack is running in from the butt, under the pad, go find a straight grained hardwood dowel, then you can drill a small dowel sized hole centered on the crack FROM the butt end so the hole is hidden by the pad
then roughen the dowel, smear some release aid onto the stock over/around the crack, mix up epoxy, force some into the hole, coat the dowel and "Gently Drive" it into the hole, forcing epoxy out the crack....
now, wipe off excess, protect the wood, and apply some pressure on the crack to close it up.
once dry, scrape the epoxy off the side, cut the dowel flush, and finish as normal
at least that is what I would try