If it was mine I would get a small sheet of birch veener. Look for the spots that will match the grain pattern on the shell. With a very sharp and pointy blade the veener can be cut to match the ragged hole. Same with whatever carnage occured on the inner ply or the inside layer of a solid shell. Will still be visible as a repair but much better looking than a incorrect wood type dowel with putty caked about.
Creighton