Photocopies of correspondence and photographs, taken from five albums, relating to Sclater's career, 1898-1927, including letter from FM Sir (Henry) Evelyn Wood, Adjutant General to the Forces, confirming Sclater's appointment as Bde Maj, Aldershot, 1898; seventeen copies of photographs and nine sketch maps relating to the Second Boer War, South Africa, 1899-1902, including photographs of Bloemfontein and Brandfort, Orange Free State, and sketch maps of the Battles of Modder River, Nov 1899 and Paardeberg Drift, Feb 1900; two photographs of the 13 pounder Quick Fire gun, newly issued to the Royal Horse Artillery, 1904; letter from Lt Col Rt Hon Arthur John Bigge, 1st Baron Stamfordham, thanking Sclater for congratulatory letter on the award of a peerage to Stamfordham, 1911; three photographs of Indian Army sepoys, 1912; correspondence, 1912- 1917, including letters relating to recruitment, military inspections and the availability of manpower from FM Sir John Denton Pinkstone French, Commander-in-Chief, Home Forces, Feb 1917, Gen Sir (Henry Macleod) Leslie Rundle, General Officer Commanding-in-Chief, Eastern Command, Feb-May 1916, and Lt Gen Sir (Cecil Frederick) Nevil Macready, Adjutant General to the Forces, Jul 1917; letter to Slater from Gen Sir (Francis) Reginald Wingate, relating to riots in Egypt, Jun 1920; letter to Sclater from Lt Gen Sir George Fletcher MacMunn, Quartermaster General, India, dated Jun 1921, relating to the political and military situation in India, particularly in the aftermath of the massacre of 479 Indian civilians by troops of the Indian Army, commanded by Brig Gen Reginald Edward Harry Dyer, Amritsar, Punjab, Apr 1919; printed obituary of Sclater [1927].

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.