Green’s Dictionary of Slang

(orig. Aus./N.Z.) to charge with vagrancy; thus do the crust, to serve a sentence for vagrancy.

1910		Register (Adelaide) 4 Jan. 10/3: You don’t want to ‘crust’ me. ‘Crusting’ me is no good to you. Catch me square dinkum and I’ll plead guilty.
1968		J. Alard He who Shoots Last 215: Ya should be crusted fer talkin’ rot at a time like this. [Ibid.] 262: to be crusted Comes from the saying ‘charged with the crust’ which means to be charged with vagrancy.
1983		R. Aven-Bray Ridgey-Didge Oz Jack Lang 22: Crusted Arrested for vagrancy.
1993		G. Simes DAUS.