Early days for the class I think it may be D6301 leading. Maidenhead, looking west from the Down Main platform. On the far right is the branch signals from Bourne End and Marlow (the line served High Wycombe on the GWR/GC Joint back in the day) leading on to the Bay platform and the Up Relief line. The station nameplate is also a give away, being quite long.The North British 63xx diesels were extremely unreliable, so it is little wonder that double heading was the order of the day in this view (probably a trial trip).