[pbgunrunner]

If its too long/short you can add a recoill pad of different length or cut it down, if the comb is too high you can sand it down (unlikely with a field stock), if its too low Gander Mountain and similar stores sell a "add a comb" kit that consists of several foam "comb spacers" and a neoprene sleeve that slides over the stock and spacers. It works pretty darned well, Ive used it to let customers "try" a stock before they invest in having one made. If your handy you can build up your comb with wood filler or body putty and sand it down to the dimensions your looking for. Then paint the stock black and go break birds!
Just FYI- a lot of trap guys shoot a hi rib/ hi pattern gun- ie the gun shoots higher than sighting down the barrel would indicate so they can float the target above the barrel for a sight picture. Your factory remington stock and wingmaster barrel would give you a flat shooting gun, if you try copy what the guys with a high rib gun are seeing for a sight picture you might assume that the gun doesnt fit you. You gun will work better for hunting and sporting clays though! Take care- chad