The Working Library
Apparently Washington University in St. Louis holds the William Gaddis Papers. While this doesn't do me any good, the WU people have posted a list of contents of Gaddis's "working library." But don't take my word for it:
...the William Gaddis Papers include his working library, which consists of approximately 1250 volumes that were housed in his study, the "west library," and his bedroom. The bibliography available here is a initial draft of the working library's holdings listed in alphabetical order by author. Nearly every entry is followed by a parenthetical statement, which describes from where each text was taken. This information is based upon descriptions written on packing boxes, which did not specify the exact physical order of the texts on the shelves. Also, some bibliographic entries include notes about marginalia and other distinctive characteristics of the book; these are initial, incomplete notes, which will be completed once the collection is fully processed.
This list goes from "AAA Florida Tourbook. Buffalo, NY: Qubecor, 1996. (Day Room)" to "Zamiatin, Eugene W.E. Trans. Gregory Zilboorg. New York: E.P. Dutton, 1952. (3rd from top Shoe)." Somewhere near the middle is a copy of Les Reconocimientos, trans. Juan Antonio Santos.
(I love this sort of thing. I imagine these scenes:
--Honey, where's the Florida book?
--The book, the Florida book. The AAA thing?
--I think it's in the dayroom, darling.
But maybe it's just me.)