Green’s Dictionary of Slang

(orig. theatre) a sovereign or pound note; in pl., money.

1900		G.R. Sims In London’s Heart 283: Nobody but our two selves, mate, and the stuff’s all in Jimmy o’Goblins and flimsies.
1911		E. Dyson ‘At a Boxing Bout’ in Benno and Some of the Push 119: A ’undred t’ twenty in Jimmy O’Gobs.
1912		Sport (Adelaide) 3 Aug. 14/4: They Say [...] That There are fifty jimmy o’ gobblins for the man who discovers a sober member of the Wild Kernut Gang.
1917		E. Metcalfe Handle of Sin 128: [...] put down one golden Jimmy-o-goblin-o, and pick up sixteen and some fragments that remain.
1919		Wodehouse ‘Rallying Round Old George’ in My Man Jeeves [ebook] [A]n income, after-all, is only an income, whereas a chunk of o’ goblins is a pile.
1925		N. Lucas Autobiog. of a Thief 106: No numbers on the Jimmie-o’-goblins, and people had more of ’em.
1932		D.L. Sayers Have His Carcase 128: Three hundred golden sovereigns — that’s what he turned it into. Three hundred round, golden jimmy o’ goblins.
1936		T. O’Reilly Tiger of the Legion 86: ‘Forty-two francs—and the exchange at about seventy-six to the British jimmy-o’-goblin!
1969		S.T. Kendall Up the Frog 34: Jimmy O’Goblin – Sovereign.
1999		Guardian G2 12 Aug. 16: My father, in his eighties, recalls that when he was a child a pound (cash) was called a Jimmy O’Goblin.