Green’s Dictionary of Slang

(orig. Aus.) a watch and chain.

1895		Herald (Melbourne) 27 Aug. 2/7: [W]hen he awoke he found that his pal had went through him for his block and tackle (watch and chain)’.
1898		Aus. Star (Sydney) 19 Oct. 7/5: Constable Ward gave evidence that when arrested Phillippie questioned him as to what he was being taken in for ‘this time,’ remarking, ‘I suppose it’s for a block and tackle affair.’ The constable explained that ‘block and tackle’ were slang terms for watch and chain.
1905		Sydney Sportsman (Surrey Hills NSW) 9 Aug. 5/5: [H]e was nabbed for pinching a block and tackle from a gentleman’s pocket.
1914		Truth (Melbourne) 24 Jan. 11/6: [headline] May Migrates With Burdett’s Block and Tackle [...] May Brown [...] was charged with stealing Albert’s watch and handkerchief.
1917		‘Banjo’ Paterson ‘Done for the Double’ Three Elephant Power 135: ‘I moskenoed his block and tackle, and blued it in the school.’ In other words, he had pawned the boy’s watch and chain, and had lost the proceeds at pitch and toss.
1923		Smith’s Wkly (Sydney) 2 June 21/2: Round the back of the stand he brought to light a brand-new ‘block and tackle’.
1928		M.C. Sharpe Chicago May: Her Story in Hamilton (1952) 132: Block and tackle – watch and chain.
1932		Sun. Mail (Brisbane) 13 Nov. 20/8: No denizen of the underworld has any other name for the purse or wallet but ‘pogue,’ just as he would term relieving a citizen of his watch and chain ‘hoisting a block and tackle’.
1949		Monteleone Criminal Sl. (rev. edn).
1960		(con. 1950-1960) R.A. Freeman Dict. Inmate Sl. (Walla Walla, WA) 12: Block-’n-tackle – a watch and chain.
1975		Bulletin (Sydney) 26 Apr. 45: He had been charged with dudding, that is, misreprsenting the iroigin, quality and value of [...] watches (blocks).