If you have occasion to scan an old paperback (or hardback) into a digital file for publishing it as an ebook, proof the resulting copy with an eagle eye.  I spent a week proofing Dan J. Marlowe’s The Vengeance Man, first published in 1966, and I must have turned up 40 or 50 instances of mistakes the OCR (Optical Character Recognition) software made in scanning the book.  The process works, but it is labor-intensive. Eventually we’ll get to Marlowe’s novel The Fatal Frails, first published in 1960.  We’ll proof it, and it will come out looking very nice, I’m sure, but it will be hard to capture the flavor of the original cover.