Green’s Dictionary of Slang

a liberty; usu. in phr. taking libbos.

1961		(con. early 1950s) J. Peacock Valhalla 43: We got libo; but we’re broke.
2000		J.J. Connolly Layer Cake 28: He was one of the first to realise that taking libbos [...] taking the piss outta the old bill, was a mug’s game.