To help ease tensions, from the UN website http://www.un.org/aboutun/unhistory/
The name "United Nations", coined by United States President Franklin D. Roosevelt, was first used in the "Declaration by United Nations" of 1 January 1942, during the Second World War, when representatives of 26 nations pledged their governments to continue fighting together against the Axis Powers.
The two films are dated 14 June 1943; and "issued" 8 July 1943. Judging by the vehicles on parade, I don't think there can be much doubt about when this event took place.
Yes! A Bedford exists, albeit with a GS body - I attach a picture of it from many years ago. (Looking again, the style of wheel arches suggest this may be a genuine portee body.)
There is also an Austin K5 Portee in preservation - see http://hmvf.co.uk/forumvb/showthread.php?21655 and Military Machines International magazine, December 2010.
Does anyone have an opinion on the vehicle colour schemes? The quads (CMP & Guy) are clearly "desert sand". But I can't make out whether some of the others are olive drab and dark green/black, or desert sand and black - the film is too washed out for my eyes.
Interesting to see the Morris Commercial CDSWs have RAF roundals on their bonnets.