Jarzębowski was also an assiduous collector, since before the war, of Polish Militaria and historical materials related to the November and January Uprisings. Fawley Court housed a Museum of national significance and was the subject of a detailed study published by the National Library of Poland. The collection comprised a number of sculptures, most notably an Antonine period marble bust said to be of the juvenile Commodus, that Fr. Jarzębowski had brought back from Mexico in 1944. It had been on loan to the Ashmolean Museum (1973–1985) but after a failed attempt to sell it in 1985, it was finally sold at a Christie's auction in 2005. Also sold in 1985 was an earlier acquisition, by a previous owner of Fawley Court, John Freeman, of a fragment from the Pergamon Altar that Freeman had placed over the entrance to the Gothic folly in the Capability Brown designed grounds. The Jarzębowski collection also contained: an armoury of the 16th–19th centuries of European, Asian and Far Eastern provenance, other militaria ranging from the last Polish uprising to World War II, French, Portuguese and Polish tapestries of the 16th-18th centuries, Italian Baroque paintings, drawings, including by Annibale Carracci, sacred art including icons, coins, medals and a notable philatelic collection.