Green’s Dictionary of Slang

thieving hooks n.

the fingers.

1821		‘An Amateur’ Real Life in London I 415: Tip us your flipper* [* Tip us your flipper — your mawley — your daddle, or your thieving hook, are terms made use of as occasions may suit the company in which they are introduced, to signify a desire to shake hands].
1823		Devizes & Wilts Gaz. 25 Dec. 4/1: If you lay but one of your thieving hooks upon a digit of her corporeal substance, faith I’ll break my arm across your face.
1846		Manchester Courier 10 June 5/2: He contrived, though not very dextrously, to insinuate his thieving hooks into Mrs Hilton’s pocket.