Convert LaTeX file to html / markdown and ePub format

I've a latex book that's publicly available (both the LaTeX files and PDF) that I'd like to be converted into html / markdown and epub format. It's a maths / statistics book so there are quite a few math formulas and also some tables and lots of images. It's important that the resulting epub reflows correctly for different readers.

The LaTeX files contain quite a few legacy packages and so there might be some updating required first. The files are here: https://github.com/davidfoxcroft/lsj-book

Thanks