About to recommend Hans Tuzzi to yet another librarian, I realized that I was more than half way to a llist of detective stories featuring rare books. So, time to make a list.
Sayers, Dorothy. Whose Body? The very first Lord Peter mystery begins with the interruption of a shopping trip to snap up some incunabula…as one does. The only Lord Peter mystery to be out of copyright in the US.
Tuzzi, Hans. Il Principe dei Gigli. Technically, this story features rare book librarians, not rare books.
Leon, Donna. By Its Cover. Nothing worse can happen to a special collection or rare book library than to have a successful thief on the inside. Set in today’s Venice but with nods to Aldus and Venice’s rich book and printing history.
From the intrepid @marccold on Twitter:
Dewey Decimated by Charles A. Goodrum;  Murders in Volume 2 by Elizabeth Daly;  Nun Plussed by Ralph McInerny; much of the Lord Peter Wimsey short fiction; and The Name of the Rose. This last makes me ambivalent, because it’s been so long since I’ve read it that I can’t remember if there was an idea of rare books within the narrative. Lost or missing texts are similar, but I had in mind rare books as collectibles after the advent of printing. That said, on the grounds of the Baskerville connection (Birmingham or Baker Street, either will do), to say nothing of fondness for the young Christian Slater, Eco’s work fits.