I'd imagine his heirs burned it.
I found this article years back, and I've always wondered about that "illustrated poem" of the evil nymph tickling the beautiful young girl. I've never seen anything like that. Surely that would be one of the ultimate mainstream finds...
(BTW, we should bear in mind that the guy discussed in the article is a bit worrisome. He was obsessed to the point of ruining his life, and his fantasies were extremely violent, ending in death...)