The collection consists of correspondence, manuscripts by Messner and others, memoirs by Messner, photographs and printed materials. Manuscripts by Messner include a typescript (275 p.) entitled "Nekotorye prichiny porazhenii︠a︡ Germanii v voĭnu 1939-1945 g.g." Messner's memoirs (3293 p. and 350 p.) cover the years 1914-1973. Included among them are clippings, photographs, mimeographed materials and pamphlets. The majority of his memoirs concern World War I and the Civil War. Photographs are mostly copies. Printed materials consist mostly of clippings of articles by Messner in South American monarchist periodicals.

The papers consist of correspondence, manuscripts, photographs, a subject file, and printed materials. The correspondence includes a letter from Randall Thomas Davidson, Archbishop of Canterbury, and one from Nikolaĭ Roerich. There is an essay about Metropolitan Platon by I︠O︡ann Chepelev, and a number of photographs depicting church officials and White army leaders. There is a subject file concerning Platon's meeting in 1919 with President Wilson. The collection also contains articles and clippings by and about the Metropolitan, and there are several books and pamphlets as well. The materials were collected by his daughter and grandson; many of the items are photocopies.