What would you like to know?
Don't really need stripper.... shellac dissolves in alcohol. take it all apart, start swabbing it with denatured alcohol, and it will eventually soften up and wipe off.
The oil finish is really easy.... use a boiled linseed oil or a pure tung oil, scrub the first couple of coats in with 0000 steel wool, then hand rub the last coats... leave at least 24hrs drying time in between coats.
My favorite resource for redoing stocks is here:
Surplusrifle Forum • View forum - Stock Care and Replacement Stocks
There's tons of good information in the stickies, as well as a lot of good people available to answer specifics if you need addt'l help.
4. The best way to measure a bore is to "slug it". Get a lead round ball a little oversized of the bore and shove it through the barrel, then mike the widest part.