75026 with presumably a Welshpool train and the Swindon Cross Country DMU on, presumably, a Central Wales line service, later in the decade they had headlights fitted for the ungated crossings.
The DMUs appeared on the Central Wales Line when the Swansea Vic to Pontardulais line closed 13th June 1964 - services then ran to Llanelli and reversed to Swansea high Street.