why put it in html at all just get the pdf and convert pdf to epub. that is what i have done with all the my books that i have made to ebook's then i figured it was worth it just to send it to a manuel company so i don't have to fart a round with the stupid free software that never works well enough to submit my books to the main web stores . it was cheep and i got indexing i was vert happy with the formatting to! it looks and feels just like the print book
pdf to epub