Green’s Dictionary of Slang

1. a coin.

1725		New Canting Dict. n.p.: spanks Money, Gold or Silver: He has Spanks enow to save his Nub. He has Money enough to save his Neck.
1737, 1759, 1760, 1776		Bailey Universal Etym. Eng. Dict. [as cit. 1725].
c.1750–1882		B.M. Carew Life and Adventures.
1785, 1788, 1796		Grose Classical Dict. of the Vulgar Tongue n.p.: Spanks, or spankers, money.
1811		Lex. Balatronicum [as cit. 1785].
1823		Egan Grose’s Classical Dict. of the Vulgar Tongue.

2. (UK und.) contr. with the, Petticoat Lane (properly Middlesex Street) London E1 [used to suggest the premises a fence-cum-pawbroker, usually run by the Jews who ran most of the local market stalls].

1899		Sketch (London) 22 Feb. 18: ’They’s a lot of stryte “fences” up at the “Spank” (that’s Petticoat Lane)’.
1899		Sketch (London) 22 Feb. 18: ‘They had done it in at the “Spank” an’ we divides up six quid (sovereigns), fer it was a nice red lot ’.