6004 'King George III' entered traffic in July 1927, being allocated to Laira on August 25, 1927 where it remained until October 1941, when the locomotive moved to Exeter. A return to Laira took place in January 1942 and 6004 'King George III' was still allocated there on December 31, 1947, although the locomotive was actually at Reading workshops for running repairs that night.