|a basic copyright question|
I have come into possession of a few old, valuable books, digitized as plain text. They are all over 150 years old, rare works by a well-known author, and I'm led to believe that they aren't copyrighted any more.
So, if I take this text, format it myself, put it in a nice typeface and produce a well-crafted PDF, can I sell it?
Other publishers reprint old books all the time, but I don't know the legalities of it all.
Short answer, yes. Public domain text and illustrations are commonly repackaged and sold. There are publishing houses that specialize in reprinting public domain works. Dover Publishing, while not necessarily one of the 'elite', is probably one of the most familiar.
The problem you could run into with a PDF presentation is that people tend not to 'read' online. Project Gutenberg does exactly as you describe. Depending upon the title, they may offer several editions. A title may be available as .txt, formatted in .html, presented as PDF, or even have one or more audio editions available. Project Gutenberg works are free to the public. In fact, their Copyright FAQ [gutenberg.org] page is a pretty good layman's reference, IMO - though you'll still want to be thorough on due diligence. There are some unexpected exceptions, such as trademarks (note 1.7 C.7 in the Gutenberg FAQ).
I would package the PDF in Chapters so as to be more user friendly, and maybe build in some jump-links to any natural breaks within a chapter.
One of our Site Maps, while orderly and complete, was also tedious. We started out by adding (for no particular reason) quotes from Alice's Adventures in Wonderland between sections. Though they made the page even longer, they added nice section breaks, made the page more fun, and the extra background-image: for the quotes helped break the page visually. We got some good feedback and wound up reformatting the entire book and offering it as an extra. Direct links to each chapter in HTML and feedback has been great. It has nothing to do with our site at all, but users love the 'fun' aspect of the offering. It was well worth the work. We even went back and added a nice set of public domain illustrations.