57mm,
Not forgetting that Major Dennis Healey was at one time the beach master at Anzio in 1944 as well as serving on the front line in North Africa, Sicily and Italy...
And also not forgetting that Sergeant Fred Mulley was captured in France in 1940 and spent 5 years as a POW. He was also up until the early hours in the House of Commons (in the period before time limits on debates was brought in) the night before the Royal review...