The collection consists of drafts of lectures, unpublished essays, and reprints by Brendel primarily on Etruscan art as well as a complete transcript of Symbolism of the Sphere. Notably, the collection also contains a dossier on the Etruscan Diana scuplture forgery purchased by the The City Art Museum of St. Louis in 1953. Brendel was one of the experts declaring the sculpture to be authentic. The sculpture was later delcared to be a forgery most likely created by Alceo Dossena. The dossier on the forgery contains correspondence, photographs, and reports.