I have a part of pdf for you attached. I have online access to softcopy of books that I have purchased in hardcopy. I printed the chapter out with bullzip pdf printer for portable use. They look good, but they are not a pleasure to look at on e-Ink maybe because of thin or grey font.
Mayebe you could do like increasing contrast or adding to thickness of font without editing methods, because the whole book makes like 50,000 pages on this format.
in advance.
Sample.pdf