i patch a lot of military rifle stocks, i try to match up but sometimes i don't even know what species of wood was used originally. i copy the old arsenal repairs that the old commonwealth armourers did as best i can, nice tight fitting patches with no gaps, blended in as best i can but not worrying too much about it. it is, after all, part of the history and character of the piece. if done well it adds good character, if sloppy, then not so much.
many old arsenal repairs will have patches dovetailed in as well.
i used titebond III, it is waterproof and seems to stay slightly flexible