Based at Landore in the early ' fifties " Drysllwyn Castle " had a reputation as being an indifferent performing member of the " Castles " at that shed which was famed for the invariably well turned out engines on the top link workings from South Wales to Paddington.
In early 1956 , however , 7018 underwent an extensive overhaul at Swindon Works during which it was to become the first of its class to be equipped with a double chimney , following the success of such modification to the " Kings "so fitted .
This overhaul transformed 7018 into becoming a much more able performer , and the engine was shortly after return to service transferred to Bristol Bath Road shed from where it was rostered on the tightly timed workings such as the " Bristolian " in both directions between Temple Meads and Paddington. Here it passes the engine shed with a down express.