An unusual place for a County, must be off a freight or was this when Landore was being re-built as a diesel depot?

Peter Kerslake says "A "Stranger in the Camp" here at Port Talbot's Duffryn Yard M.P.D. in the 1960's with 1013 "County of Dorse " on shed, both her washout plug covers lifted indicating she is to have, or has had, a boiler washout of accumulated muck and dirt from her firebox.
1013 had been a Shrewsbury "County" a few years earlier, rostered regularly on the "North to West" workings and running from her home at Shrewsbury down to Newton Abbot, returning home the following day, but she's probably here in Wales from an express freight working.
Duffryn Yard was primarily a freight centre, with heavy demands on its locomotives for working the steel freights in an area which was the steel production centre of Wales, the Depot dating back to the days of the Port Talbot Railway in 1896 when it was established as a five road layout, subsequently enlarged by the G.W.R. by an additional track being installed in 1931, the shed remaining in service until March of 1964."