Green’s Dictionary of Slang

one’s furniture or household effects.

[1785		Grose Classical Dict. of the Vulgar Tongue n.p.: Kit [...] the whole of a soldier’s necessaries, the contents of his knapsack].
1796		Grose Classical Dict. of the Vulgar Tongue (3rd edn) n.p.: Kittys. Effects, furniture; stock in trade. To seize one’s kittys; to take his sticks.
1811		Lex. Balatronicum [as cit. 1796].
1823		Egan Grose’s Classical Dict. of the Vulgar Tongue [as cit. 1796].
1859		Matsell Vocabulum 49: kittys Stock in trade; tools. ‘The bobbies seized the screwsman’s kittys,’ the officers seized the burglar’s tools.
1895		C. Crowe Aus. Sl. Dict. 42: Kittys, one’s stock-in-trade; tools.