For several years my family has been trying to find out about this picture, which shows my late father Arthur Rowland (to right of centre) talking to a naval officer during WW2.

The picture is stamped as copyright the News Chronicle, and the Imperial War Museum believes that the officer is Admiral Sir Bertram Ramsey, who was Commander of Dover and responsible for the evacuation of Dunkirk. They also say that the helmet my father was wearing identifies him as a Stretcher Party Supervisor in the Civil Defence Services (aka ARP for Air Raid Precautions), which we did more or less know. He was in the ARP in London, I think throughout the war, and is possibly one of the sources for a story that Gerald Kersh wrote about the ARP - my father knew his publisher, and may have known Kersh although I'm not 100% sure about that. About the only thing I can add is that I think that the man on the extreme left has the words "Depot Supervisor" on his helmet, which to me suggests that the picture was taken at an ARP depot.
The trouble is that this picture was more or less forgotten until after both of my parents had died, and we have no idea when or where it was taken, or what the occasion for it was - records appear to be more or less non-existent, and so far the picture hasn't turned up in microfilmed archives of the News Chronicle at the British Newspaper Library in Colindale. It would be nice to know more. Our last surviving relative of that generation was my uncle, but unfortunately he spent WW2 in the Far East, and was as puzzled by this picture as we are.
There's some evidence that this was after October 1943. In this picture Ramsay has the rank insignia of a full admiral. During Dunkirk he was still a Vice Admiral. In the summer of 1942 he was promoted and sent to Gibraltar to plan for and later command the naval aspects of Torch. In October 1943 he came back to the UK as the Naval Commander for Overlord. He died on January 2nd 1945, so this is presumably 1943-4.
If anyone can shed any light on this, or suggest any sources we could try, I'd be grateful for their help. Please feel free to pass this on to anyone who might know anything relevant. As noted above I've already tried the Imperial War Museum and the Picture Post archive, and I've just emailed the Civil Defence Association to see if they know anything.
Later edit - forgot to say that it would be interesting to know the identities of other people in the picture, if anyone recognizes anyone else.