In the 1950s Hargrave earned a living as a cartoonist, working under the name of 'Spiv' or sometimes just 'H'. His work appeared in "Cavalcade", "The Sketch" and "Time and Tide". He was commissioned to write the entry on Paracelsus for the "Encyclopædia Britannica" (Hargrave had published "The Life and Soul of Paracelsus" in 1951). He submitted a stream of manuscripts, radio plays and film scripts to producers and publishers, always searching for opportunities to realise his ideas: he continued to believe that Social Credit was the solution to the world's economic problems. John Hargrave died on 21 November 1982, aged 88 at his home in Branch Hill Lodge, Hampstead.