Displaced in late 1959 from its then home at Pymouth's Laira's shed, 6004, "King George III" spent just nine months at Old Oak Common before another move saw it reallocated to Cardiff Canton, where it joined a number of other "Kings", working out their final time in service as suitable work on their previous routes was being increasing taken over by the advancing Diesels.
The shedmasters at Canton doubtless had difficulty in finding suitable wok for their newly acquired "Kings", particularly as many of the express passenger workings between South Wales and Paddington were, as they had been for some time past, being entrusted to the Landore and Canton "Castles", all maintained in fine condition.
Those "Kings" at Canton did, however, appear on a number of those same principal express duties from time to time, but a number of Canton's "Kings" were later stored out of use at that shed as suitable work became increasingly difficult to find.
6004 was finally withdrawn from Canton in September 1962, being disposed of at Swindon that same November.