Bradley, Carol W. Miss Pinn: the Case of the Missing Librarian (San Francisco: Bird in Hand Press, 1975.) Linoleum cut illustrations by Bruce Wm. Bradley.  p. No. 190 of a 200-copy edition.
"Miss Elvira Pinn was an efficient, but slightly absent-minded librarian." When she disappears Mr. Broome the janitor and Mrs. Pagge the Head Librarian (who knows exactly where every book is located) go looking for her.