Well, it doesn't look that bad the way it is. In this case I don't think the area should opened up for the patch piece. I think a new chip should be found/made to fit the existing chip as closely as reasonably possible. Finding a piece with very similar grain structure is the first challenge. The next challenge will be to make a chip that fits into the impression very closely and has the grain alignment right. I think I would drill some holes in the donor piece, and purposely chip out the wood until you get a very close match to the missing chip then epoxy it in with very light brown epoxy and carefully work it back to shape with as little disturbance to the finish as possible.