Green’s Dictionary of Slang

shelfer n.1

[ety unknown]

(Aus.) a bookmaker.

[Aus]Sun. Times (Perth) 14 June 1/1: This notorious old shelfer is a kidder of porcine principles.
[Aus]Sun. Times (Perth) 21 June 4/7: ‘Because,’ explained the shelfer, ‘I ain’t got no vun to settle with’.