Peter Kerslake says "A splendid overhead view of Railcar W6W at Arley in 1954 , this member of the class being one of six based at Worcester at about this period in time so understandably being on this Severn Valley line. One of the early versions , built in 1935 , this Railcar was one of three introduced by the G.W.R. for a prestigious Cardiff to Birmingham express service and had a miniature buffet on board as well as toilet provision together with no less than seventy seats . The service was so popular that demands soon exceeded the capacity of the Railcars , which had to be replaced by more conventional steam hauled rolling stock . The total of 35 remaining Railcars in service in late 1956 were distributed over no fewer than thirteen Motive Power Depots , with Worcester having the most.

I may have been incorrect in my earlier comment that Railcar number 6 seen here worked the Cardiff to Birmingham services in early 1934 as further research indicates that just numbers 2 , 3 and 4 might just have so been employed with number 6 being from a later 1934 batch dispersed from new to depots such as Bristol St Philip's Marsh"