I had a problem where my piano was dropped off the truck.  It was
in a protective case but there was still crush damage to the corner.
The first "professional" that repaired it basically filled it with
colored epoxy, and it looked as bad as that sounds.

When I had the piano restored, the technician built a piece to match
the corner that was missing.  He glued this in place then carefully
matched the veneer and mated them.  When he was done I couldn't detect
the repair, even when looking directly at it with a bright light.  Of
course the piano was refinished and French polished after the repair.

Good luck,
Eliyahu Shahar