In 1946 Flying Scotsman was rebuilt to A3 Class specification and emerged in January 1947 having been renumbered by LNER as No. 103. In December 1948 Flying Scotsman was once again renumbered as a result of the nationalisation of the railways, becoming No. 60103. In 1954 the locomotive was converted to left hand drive and painted into BR Green, also known as Brunswick Green.