Here is an update, with current thinking on identities:
Identified group members in photo taken early July 1922
5 Donald Sterling Palmer Howard, 3rd Baron Strathcona and Mount Royal.
6 John Simon, 1st Viscount Simon, later to become Home Secretary, Foreign Secretary and Chancellor of the Exchequer: in 1922 he was MP for Spen Valley and deputy leader of the Liberal Party. Husband of No 25.
11 Sir James Allen, NZ High Commissioner. He was appointed an Officer of the Legion of Honour in February 1922 when he was High Commissioner in London.
12 Sir Frederic Kenyon, Director, British Museum
13 Sir Reginald Theodore Blomfield (architect of Menin Gate, Ypres)
14 US Chief Justice William Howard Taft, formerly US President. On three week fact-finding visit to Britain, 16th June-8th July 1922
15 Helen (“Nellie”) Taft, wife of No 14
19 Sir John James Burnett, architect of War memorials at Gallipoli, and Jerusalem
20 Sir Robert Stodard Lorimer, architect of the Scottish National War Memorial at Edinburgh Castle
21 Lt.-Col. Herbert Thomas "Tom" Goodland, Deputy Controller IWGC
22 Captain William Masters, R.A.S.C.
24 Major General Sir Fabian Arthur Goulstone Ware KCVO, KBE, CB, CMG, founder of the Imperial War Graves Commission, now the Commonwealth War Graves Commission
25 Kathleen, Viscountess Simon, Wife of No 6
26 Prince Arthur, Duke of Connaught and Strathearn, son of Queen Victoria. Note black armband: he is in mourning for the death of his close friend Field Marshal Sir Henry Hughes Wilson, shot by IRA gunmen in London, June 22nd 1922.
27 General Sir Horace Lockwood Smith-Dorrien, Governor of Gibraltar. He devoted much his time to the welfare and remembrance of Great War soldiers.
28 Carrie Kipling, wife of No 30
29 Elsie Kipling, daughter of Nos 30 and 28
30 Rudyard Kipling, author. Kipling's role was to advise the IWGC on inscriptions and other literary matters, and he was a founder member together with Tom Goodland (No 21) and others of The Builders of the Silent Cities, a Masonic lodge for IWGC staff.
31 Captain George Louis St Clair Bambridge, Diplomat, of Wimpole Hall, near Cambridge: will marry No 29 in 1924
Thanks again to everyone for their help: will report back once I get a response from CWGC and the Lodge
Paddy