[stash247]

Cougar, start with truly dry wood, from whatever source, but wood at below 7% moisture.
Plane smooth the 'top line', and locate the stock screws, then drill the holes for them, and use over long screws, to locate the action, over the wood. Scribe the waterline dimensions, on the top line of the stock,and cut away all the wood that interferes, until the action is totally in the wood, without a gap, anywhere, to the waterline, then do the outside shaping, to your specs.
I like a Urethane finish, reduced with Tung oil, to seal all surfaces, as the wood must be protected, inside, and out from moisture intrusion, as a defense against warping.
I move the wood with chisels from Jos. Henkels' "Twinworks", because they are the best I have found, anywhere, but they are not cheap; expect to pay 20-30 dollars, each, for tools of this quality, and have or buy a buffer, to keep them razor sharp, as they are useless in lesser condition.
If there is a gunsmith, or stockmaker, in your area, the 'time efficient' way is to use a 'stock duplicator', to move most of the wood, then finish with the chisels, using the original stock as the 'model', having added what you want, in dimension, with 'bondo', to it's exterior, then copying it, on the machine.
Some will turn only the wood they supply, some, your wood or mine; ask first, and play it by ear!
If you are going 'whole hog' into the business, buy such a machine, and maintain it well; the best out there, IMHO, are those from George Hoenig, in Minnesota, offering accuracy in the .005" range.
Good luck, and Happy Holidays!