Green’s Dictionary of Slang

bass and flinders n.

[rhy. sl.; Aus. pron. ‘winders’; ult. Aus. explorers George Bass (1771–1803) + Matthew Flinders (1774–1814)]

(Aus.) windows.

[Aus] ‘Whisper All Aussie Dict.’ in Kings Cross Whisper (Sydney) xxxii 6/1: bass and flinder: Window.
[Aus]R. Aven-Bray Ridgey-Didge Oz Jack Lang 18: Bass and Flinders Windows.
[Aus]G. Seal Lingo 89: Names of prominent, and even not so prominent, people, and even department stores, have always proved fertile sources of Australian rhyming slang, such as bass and flinders winders (windows); captain cook look, as in take a captain cook at that, also used in Cockney rhyming slang.