Agree, a cracking find.
History here.
//Cuthbert A man with a cushy job in a government office, especially one who avoided military service on the score of occupation. Personal name supposedly suggestive of effeminacy.
General. From 1917 (OED). Attested in numerous sources.
F&G provide the following explanation: ‘A name in the War, coined by “Poy”, the cartoonist of the Evening News, and colloquially adopted by way of contempt for fit men of military age, particularly in Government Offices, who had been “combed out” for the Army. ... In “Poy’s” cartoon the “Cuthberts” were represented as frightened looking rabbits.’ ‘Cuthbert’ was also used to refer to a conscientious objector.//