Looks good! One minor point: it looks like some of your conversion isn’t keeping accurate styling. For example, if you look at the letter in https://standardebooks.org/ebooks/edgar-allan-poe/short-fict... that starts with “In conformity with an order” you’ll see (in Firefox and Chrome, Safari’s in the process of adding the styling) that the address is 90º as per the original scans. The same in https://flowery.app/books/edgar-allan-poe/short-fiction/thou... falls back to normal display, which is fine but perhaps a little bit of a shame.