At the risk of looking a gift horse in the mouth, the ePub versions I tried are rather unreadable, at least for me. Too many erroneously omitted spaces between words, odd hyphens breaking a word up in the middle of a paragraph, and mis-spellings.
If you have low quality source, eg OCRed scans, then you’ll never get a high quality ePub. It needs manual intervention and proofing to keep quality up. Not to say that archive.org isn’t useful - I’ve produced a collection of Keats poetry[1] as an ePub from their OCRed source in the past - but it’s not really consumable as is.
Yeah, I came here just to say that. I downloaded and unzipped the archive, then opened a few. The ones I looked at were badly formatted and had no TOC as well.