Talk to Vicki Keen of Keensights (http://www.keensights.com). She has done several ribs for me, all perfect, no subsequent problems, and the price is very good.
She does it by manufacturing an aluminum rib specifically to fit your gun and then attaches it to your gun by a combination of screws (using the bead screw holes already on your gun) and something like RTV. (You can't see the RTV when she is done.)
I recently compared one of her ribs (on my gun) to a Moneymaker rib (on a friend's gun) and found no reason to prefer the Moneymaker rib. While opinions might differ, I though her rib looked a little nicer than the MM. It is also easily removable, if you want to sell the gun as pristine.
Quite a few people posting on TS.com have spoken favorably of Vicki's product, and I don't recall ever seeing any indication of dissatisfaction.
Also, she is a pleasure to deal with.
Ted K.