I am trying to construct a model of Kerne Bridge station on the Ross to Monmouth railway. This railway was operated with a 14xx driving a common or garden Autocoach most of the time. I have a number of photos and video of an extra Autocoach added to the train in front of the original Autocoach. I am trying to identify the origins of this single window Autocoach so that I can endeavour to make a model of it. Please help.