Oscar Gnosspelius, the model for Timothy (or Squashy Hat) in Pigeon Post, trained as a civil engineer and went to Brazil and the Transvaal in the 1910s; but to carry out land surveying not mining or prospecting.
Before the Great War he designed aircraft, and was a Major in the RFC/RAF in the war. Postwar at Short Bros the seaplane manufacturers he designed the “ultralight” Gnosspelius Gull (which had a modified motorcycle engine, the Blackburne Tomtit, a 696cc Vee-twin of 16 hp) for the 1923 Lynpme light aircraft trials. Tomtit No 2 crashed, killing the pilot, in 1926.
He married Barbara Collingwood in 1925.
He was a friend of Arthur Ransome, and in 1935 advised him on mining and prospecting for Pigeon Post, which is dedicated to him. He is a prototype of the character Squashy Hat (CFT5).