The Joseph Martin Kraus Collection was gifted to the Library by Fredrik Samuel Silverstolpe, who himself had copied a large number of the Kraus' scores.
The Collection also contains manuscripts written by the composer himself. It comprises approximately 100 works by Kraus, most of which are in partiture. There is no special catalogue, but the Collection is incorporated in the general music catalogues. The content of the Collection is described in the book below.
The shop in foyer of Carolina Rediviva sells recordings of music from the Kraus Collection.
Reference
van Boer, Bertil H. Jr., Joseph Martin Kraus. Styvesant, N.Y., 1998.
The Section for Manuscripts and Music is happy to assist you with your searches. You can request a document and study it the same day, here in the Special Reading Room in the Library.