GWR County class 4-4-0 No 3821 County of Bedford pilots a 43XX class 2-6-0 seen passing Iver with an up express for Paddington in c1920.

Peter Kerslake says "Distinctive with its curved front frames, 3821 was the first of the 1911 built third batch of the "County" class, This final batch also had copper capped chimneys, together with screw reversing gear and superheated boilers with top water feed."
Photo: Robert Brookman/Rail Archive Stephenson