Sound's like you're getting there, Sir Charles! The size of the dowel would depend on the ammount of wood available to drill the hole in, I guess. Fortunately, it probably won't be used too much for bayonet drills, so the dowel and acraglass or epoxy should be plenty strong enough.
Charles Issac, looks like nice work on your Krag stock, too. But....Just how many Krags ARE you hoarding?
Mustang Gregg...Only possible problem I can see with restoring a Mauser with a commercial barrel is, doesn't the rear sight on most Mausers mount on a sleeve that fits around/then silver soldered to the barrel? (I haven't pulled one out from the safe to check, but that's how I remember them working). So that would mean either turning the barrel to origional contour, or reaming out the sight base to fit. But if I'm wrong and the base just sits on top of the barrel, then it wouldn't be too hard at all to fit the origional base to the commercial barrel.