Previously G-APUP, rebuilt from a wreck. It was cancelled from the register in 1984 when it was transferred to the RAF Museum. For a full, very detailed history https://www.rafmuseum.org.uk/documents/collections/82-A-1067-Sopwith-Pup-N5182.pdf
Australia's highest-scoring ace, Robert Alexander Little, achieved his first aerial victories flying this Pup, named Little Maud, whilst serving with with No 8 (Naval) Squadron on the Western Front in late 1916 and early 1917. Found as a heap of parts in France, the aircraft took to the air again in 1973 as G-APUP after a 13-year rebuild, and was recognized as original by the CAA.