Green’s Dictionary of Slang

a gold coin; in pl., money; often ext. as red ruddock, golden ruddock.

1567–70		G. Turbervile ‘Of Two Desperate Men’ in Chalmers Eng. Poets (1810) II 647/1: The greedie Carle came within a space [...] and saw the pot behinde / Where Ruddocks lay.
1575		Appius and Virginia in Farmer (1908) 26: Haste for a hangman in hazard of hemp! Run! for a ruddock there is no such imp.
1585		‘S.R. Gent & Student’ Choise of Change Sect. Triplicitie of Poetrie No. 92 n.p.: Whosoeuer will retaine a Lawier [...] must haue his red ruddocks ready, which he must giue to his Lawier, who will not set penne to paper without them.
1599		Nashe Praise of the Red Herring 21: The redde herring [...] brought in the red ruddocks.
1600		Munday & Drayton Sir John Oldcastle I ii: My fingers’ end do itch To be upon those golden ruddocks.
1605		Shakespeare London Prodigal B3: He hath the nobles, the golden ruddockes.
1631		T. Heywood Faire Maid of the West Pt I II i: I beleeve they be little better than pirats, they are so flush of their ruddocks.