Initial livery after nationalisation in 1948 was British Railways malachite green and "Sunshine yellow" lining and lettering, with British Railways on the tender. No. 34090 "Sir Eustace Missenden, Southern Railway" was given commemorative malachite green livery that included green-painted wheels with yellow rims and the early British Railways crest on the tender. The Bulleid numbering system was temporarily retained on the first seventy locomotives with the addition of an "s" prefix (e.g. s21C101). The classes were given several power classifications in their careers, beginning with 6MT (Mixed Traffic) in 1949. In December 1953 they were reclassified 7P 5FA, the "A" denoting brake power when used on unfitted (non-vacuum braked) goods trains. The rebuilt locomotives retained this classification until all received the classification of 7P6F between November 1957 and November 1961. The locomotives were turned out in British Railways Brunswick green livery with orange and black lining with the British Railways crest on the tender side, after their first overhaul under new ownership. This was unlike the Merchant Navy class, which was initially turned out in British Railways experimental express passenger blue livery. By this stage, the Southern Railway-built locomotives were re-liveried and renumbered from 34001–34070. The rebuilt locomotives were also in British Railways Brunswick green with orange and black lining, and crest on the tender side, whilst the nameplates were placed on a custom-made mounting on the running plate due to the absence of a flat surface. Some of the locomotives had additional embellishments. No. 34050 "Royal Observer Corps" was presented with an ROC long-service medal in July 1961. The ceremony took place at Waterloo station, and included Commandant ROC Air Commodore Wight-Boycott. The cab side was given a representation of the medal and its ribbon, which was displayed until the engine was withdrawn from service and scrapped in the late 1960s. The original nameplate and crest were recovered and displayed in the entrance hall of ROC Headquarters at RAF Bentley Priory until 1996 when they were transferred to the RAF Museum at Hendon. Another locomotive that featured a second crest was 34067 "Tangmere", which was given the airfield's crest for the cab side, as it did not feature on the nameplate crest. The class in both unrebuilt and rebuilt forms has been the subject of divergent opinions.