Possible Clues:

• A divine will finish the extra bit with `Um'
• A learned doctor might finish with 'Um!', but it's all put on
• Supplement, appendix
• Swell finish to middle jump for rider
• Supplement menu with threepenny bits
• A divine death? Um, there's a bit more to it
• Thing to be added
• Supplement to a book
• Something appended as to end of book
• Put together measure that's pronouncedly stupid at the end