Q
Light will probably smack me down for saying this but I was thinking you could get a two part wood epoxy repair kit. You can pick the stuff up at Home Deport or Lowe's. Mix up a little, it works up into a clay like consistency. Remove the jack, plop a bit of the wood repair stuff into the cavity, shape it as needed to build up the surface then drill it out for the threaded shaft of the jack.
But, you'd better ask Light what he thinks. I remember him once say that epoxy has no place in a guitar. He could be right.