I found an edition of lesser known short works by Flann O'Brien in an australian university's library (I worked there) with a stamp on the lending sheet to the effect: "pulped if not loaned within the next 6 months" and I promptly borrowed the book on the strength of it.
I was not disappointed. A strange tale of solving Irelands famine problem with Sago palms, and a very odd story of a heroin-addict carpenter who walls himself up inside the panelling he is lining a room with.
There was another uni I worked at in the UK which had a complete set of monographs published by NASA in the 60s, including guidance to emergency operations in space and prep of a corpse for re-entry. They really did their planning before the moon landings. Also all sitting there, not being read.
There is a national index of rare books that only a handful of libraries have a copy of; you can get scans through ILL.
https://en.wikipedia.org/wiki/National_Union_Catalog