LNER B1 4-6-0 No 61371 with wat the photographer recorded as the 2nd part of 8.52am Cambridge - Clacton excursion. However looking at the Special Traffic Notice in the Great Eastern Railway Society archive, it shows 2 excursion trains, 0852 from Cambridge and 0820 from Bedford and we believe (as this is made up of Stanier coaches) this is the 08.20 from Bedford. Seen here passing Shelford on 25 June 1961.

Photo: M.J. Fox / Rail Archive Stephenson