Note the very mixed rake of coaches, the BR Mk2 dates it to quite late and are those Mk1 suburbans at the rear?

Robert Waterman confirms "The Mk2's arrived in 1964 (early version with integral bodies and B4 bogies but Mk1 interiors - and double sliding vents rather than the later single vent). There are indeed 2 non-corridor suburban coaches at the rear, which arrived to increase rush-hour seating capacity substantially which arrived, if my recollection is correct, 1963/64 - some were SR green and some BR maroon. This is a typical, and booked, formation, normally SK,FK,BSK semi-open,S,S or CK,CK,BSK semi-open,S,S. they were used for Basingstoke and some Salisbury stoppers. Two sets were coupled together for rush-hour services".