My suggestion is to find a wood sculptor, not a woodworking shop. I've known some of these people and they are amazing. The shape you need to reproduce is not too complicated, so a good carver / sculptor would be able to do that. Moreover, many of these people really know wood and stains, and often have a private stock of hard-to-find wood. My guess is he / she would cut off the damaged part, fasten on a new block of matching wood, carve it to reproduce the shape, then stain and varnish. Not cheap, I'm sure, but no more expensive than a cabinetry shop might be.