A couple of different ways to do it yourself. I have seen it done with threaded lamp tubing epoxied into place but it took a lot of hand filing to get the contour right and galvanized tubing is subject to corrosion, I've also seen the screw holes drilled out oversized on a wood stock all the way through and filled to make epoxy pillars, which are poured as part of the epoxy bedding with an escutcheon on the bottom. This keeps the stock screws from pulling through if overtightened on a wood stock.
I found this while googling to try and find out how to spell "Escutcheon" http://www.youtube.com/watch?v=i5HFz1Qe20w
I'll bet Uncle Larry over at Midway or Brownells would have just what you need