Green’s Dictionary of Slang

(Aus.) remote; located in the outback.

1886		Telegraph (Brisbane) 20 Feb. 9/6: They were waiting for a train at a wayback station up in Humbolt County, and the conversation turned to spiritualism.
1892		Barrier Miner (Broken Hill) 29 Feb. 2/3: [T]he way-back farmers are being asked to believe that a greater principle is involved in the question whether eighteenpence duty per head should or should not be clapped on to imported pigs.
1941		Age (Melbourne) 14 June 19/1: [T]here would be hordes of inspectors to examine the returns of every way-back farmer and suburban shop keeper .
1953		Labor Call (Melbourne) 14 May 6/6: Another unfortunate outcome of the railway strike is the attempt to put women in charge of way-back stations in lieu of station masters.
1969		P. Adam-Smith Folklore of the Aus. Railwaymen (1971) 116: They were a law unto themselves these old time guards on way-back lines.