Morris PU: BEF Dunkirk? Unit, registration?

[S LATHERON (RIP)]

My father was a member of the BEF rear guard that fought against the German forces at Cassel. Finally being taken prisoner when the section he was in was eventually overrun. Most of the troops had run out of Ammunition and carried wounds of some sort. My father had a lucky escape when a petrol bowser took a direct hit and he was knocked over by a lump of truck chassis at the end of its flight. Must have been a flat section of steel as it did nothing more than heavy bruises to his shoulder and arm.
For the rest of the war he was a Guest of the Germans in both Poland and Germany. Towards the end of the war the prisoners were forced to march from POW camp to POW camp as the Red army looked set to over run the section of Germany that the Prison / stalag was in.
The camp was finally liberated by the Advancing US forces on Good Friday 1945.
Kenneth Latheron RIP 2007.
Stephen L