After posting the note about finding my memoir available on-line for free download, a friend sent me a note on Facebook saying, "If I were you, I'd download it immediately and see if these people have done anything to it. It's work to scan a book, and I can't imagine why anyone would do it in order to give it away."
And so I did, even before I heard from the publication rights people at The University of Iowa Press. And yes, the book is there: whole, scanned into a .pdf file, as pretty as you please.
What I did notice in following the links is that the Seven Wheelchairs is being used, along with other books, as part of a bait-and-switch operation. The book is free for the download, but a person must move through several screens offering a faster download for a fee.
The standard "cease and desist" letter is in the hands of the culprit's ISP, but as the Press told me, "unfortunately the best I can do in most cases is send them our cease-and-desist, which -- since most ISPs are in Singapore and places with loose-to-nonexistent copyright protections -- usually doesn't amount to much."
Such is the way of the world ...