File primarily contains letters from individuals, but also includes copy letters of Edith Simon. Identified correspondents include Desmond Flower, Cassell & Co. Ltd.; David Higham; Mrs. J.M. Patterson, The Royal Society of Literature; Elspeth Cochrane, TheatreWork; Robin Dalton, John Redway & Associates; Gillian Treesman, TheatreWork; Rex Stout, The Author's Guild of the Author's League of America, Inc.; 'Charles'; Molly Thomas, Little, Brown & Co.; Sheila M. Watson, David Higham Associates; possibly Rebecca West; Moya Lade, Little, Brown & Co.; possibly Robert Simon; possibly Charles Harbord; 'Colin', Her Majesty's Theatre, Haymarket; James MacGibbon, Victor Gollancz Ltd.; Collin Ellis; Jean Leroy, David Higham Associates; Dilys Waring, Chicester Festival Theatre; Richard Hughes; Ned Bradford, Little, Brown & Co.; E.S. Harper, Cassell & Co. Ltd.; Annette Carter, Cassell & Co. Ltd.; and Leo Vernon, Cassell & Co. Ltd.

File also includes 16 pages of a printer's proof of a German-language text by Edith Simon, entitled Friedrich Der Gross [translated from her English-language book The Making of Frederick the Great], stamped with the date April 1964.