On the Hunstanton portion of the 8.20am, presumably from Liverpool Street.
Peter Kerslakesays "61571 was the first of the ten additional members of her class which were ordered by the L.N.E.R. in 1928 to supplement the 71 inherited from the Great Eastern Railway. Initially numbered 8571 to 8580 these ten additional locomotives were built by Beyer Peacock and classed as B12/2s and later, in their rebuilt form as B12/3s.61571 will take this train to Kings Lynn from where almost certainly a 'Claud Hamilton' will take it down the branch to Hunstanton."