You have the two definitions and their answers. The remaining letters are the jumble of all letters used in amendments.
Count how many times you have removed each letter from answers to produce entries. Count how many times you have added each letter to an answer to produce the entry. You should find remarkable similarities which solve the problem of which letter to use in the two ambiguous entries. Once you've crossed all those letters off from the jumble in the rest of the clue, you should be left with one letter which will resolve the ambiguity between the two answers you have.