For about a decade in the early nineteenth century, the castle of Count Heinrich Wilhelm Haugwitz in Moravian Náměšť nad Oslavou hosted a large number of musical activities centered on Mozart's operas. These activities are documented in orchestral scores, manuscript performing materials, and unusually meticulous and detailed financial records. An exploration of the Haugwitz materials associated with La finta giardiniera, Don Giovanni, and La clemenza di Tito shows that due to his historicist and literary interests the Count focused on unusual German adaptations of Mozart's Italian works as well as operas that were not common in regular repertoire of the day. The Haugwitz documents also show that the Count obtained the performing materials not only from Prague and Vienna but probably also from a previously overlooked copyist workshop in Brno.