Green’s Dictionary of Slang

(Aus.) an idler, a layabout, also as term of address.

1922		C. Drew Rogues and Ruses (1923) 17: The usual gang of shifties that collect around a man [i.e. a bookmaker] when he first opens up on a race.
1934		C. Drew ‘Shakespeare Harry’s Runner’ in Bulletin 27 June 50/4: A gang of Shifties who had been bettin’ among themselves got into holts with one another, and the place was like Donnybrook.
1986		R.G. Barrett Real Thing 15: A few other ‘shifties’ who always seem to find plenty of time to hang around [...] enjoying the sun.
1991		R.G. Barrett Between the Devlin 122: ‘How are you, shifty?’.
2000		R.G. Barrett Leaving Bondi (2013) [ebook] ‘Knox waas a bit of a shifty’.