Final update for those who helped:
I created a new empty epub2 in Sigil, copied the css from the original, then spent half an hour copy and pasting the html pages from my original to the new one.
Then added an Index of Poems as a text page at the end of the book.
Did NOT tell it to Generate a TOC.
Saved and uploaded to KDP which accepted it and the proof reads exactly as it should do.
So the paperback should be fine now.
Thanks again all