broken heel advice ...

[Arnold Schnitzer]

1) Get the remaining piece out of the mortise.
2) True-up and reattach it to the rest of the neck.
3) Reinforce this somehow.
4) Clean out and true-up the entire mortise.
5) Re-fit the neck into the mortise, making sure the pitch and lateral angles are correct.
6) Glue in with hot hide glue and clamps.