Papers relating to his command of 1 Infantry Div, Anzio, Italy, 1944, dated 1943-1962, principally comprising correspondence and memoranda, 1943-1944; diary and typescript diary entries, 1943-1944; operation orders, tactical notes and maps, 1944; written accounts of operations carried out by 1 Div and individual regiments and battalions, 1944; correspondence relating to historical accounts of the landings, 1945-1962, notably Anzio by Wynford Vaughan Thomas (Longmans, London, 1961). Other papers relating to his life and career, 1920-1958, notably including an article by Penney on his service in Wazaristan, India, 1937, reprinted from the Royal Signals Quarterly Journal, Oct 1938 and Jan 1939; memoranda from General Staff, Shanghai, from the City Government of Shanghai and from W R Connor Green, British Embassy, Tokyo, concerning relations between the Chinese and Japanese, and the role of the British garrison in the protection of Shanghai, 1931-1933; diary, 1932, referring principally to matters affecting British troops in Shanghai; press cuttings, [1932]; anti-Japanese propaganda posters produced by the Shanghai Municipality National Salvation Committee to Resist Japan, [1932]; itinerary of Penney's movements in the Middle East and North Africa, 1941-1943; diary, 1943-1944, including description of Allied Forces HQ, Algiers, and reflections on the differences between US and British signals procedure; official and personal correspondence relating to his service as Director of Intelligence, HQ Supreme Allied Commander, South East Asia, [1945].

Papers relating to his service in the Indian Army, dated [1941], 1942, [1944], 1947, 1962-1964, 1970, 1973, 1984, principally comprising photographs of convoys at Sarwekai on the route between Mangai and Wana, South Wazaristan, India, [1941]; operation instructions for 50 Parachute Bde exercise in Tughlakabad area, India, Mar 1942; 'Some notes on Gurkhas', typescript text by Stevenson-Hamilton, 1943; typescript account of the service of 4 Prince of Wales's Own Gurkha Rifles, India, 1943-1944, written by Stevenson-Hamilton in [1944]; typescript account of the service of 2 Bn, 4 Prince of Wales' Own Gurkha Rifles, Italy, 1944, written by [Stevenson-Hamilton] in [1944]; unsigned official notes on a tour of Arakan by 98 Indian Infantry Bde, Burma, 1944; 71 Indian Infantry Bde instructions for operations in Maungdaw, Burma, Apr 1944; typescript text on Gurkha operations in Wazaristan and the Punjab, India, 1947, and on the proposed transfer of Gurkha regiments to the British Army, 1947; notebook containing notes on misdemeanours and crimes committed by soldiers at Garlochhead Training Camp, Helensburgh, 1962-1964.