Green’s Dictionary of Slang

have it away (with) v.1

to steal an object.

[UK]R. Cook Crust on its Uppers 34: There they are in court [...] down to having it away with someone’s spoons.
[UK]F. Norman Too Many Crooks Spoil the Caper 103: It don’t make no odds to me if I plug yuh where yuh stand and ’ave it away wiv the lolly.
[UK]Partridge DSUE (8th edn) 537: since ca. 1925.
[UK]J. Morton Lowspeak 71: Have it away – to successfully complete a crime.
[UK]J. Cameron It Was An Accident 71: All you got to avoid is some gangster likes his new Merc, didn’t reckon you ought to have it away.