This photo was taken from BRITAIN AT WAR IN COLOUR and shows Monty at his mobile HQ 12 June 1944. Note Leyland Retriever L 4410754 from the batch L 4410454-4410860, V.3929, "Lorry 3-ton 6 x 4 Machinery". However the query from my contact, Guy expert Robin Hannay relates to the lorry which is at right angles..Robin believes that it is a Guy [see thread relating to the reputed armoured command post used by Monty in the Desert]. He says it appears to be a Guy becase they were the only manufacturers who had a conical end on their half-shafts: it's certainly not he says an Ant/Quad-Ant, Lizard or Petrol-Electric.
Click 'ere