GWR County 4-6-0 No 1003 County of Wilts with the 3.18pm Paddington-Wolverhampton passing West Ealing on 12 April 1958. Very unusually the first vehicle is an ex-NER 6 wheeled passenger brake van probably over 50 years old and therefore surely on its 'last legs'!
Keith Morris adds "Surely a Wolverhampton train would have taken the High Wycombe line via North Acton - or if it was diverted via Greenford it would be on the relief line here ready to swing north?" I assume there were none routed via Didcot and Oxford at this time?

Photo: K.L. Cook / Rail Archive Stephenson