Partime,
The lettercard shown was issued by Queensland in 1895.
Victoria had recently raised the lettercard rate from three halfpence to two pence and Queensland took 'heart of grace' from their example.
(From 'The London Philatelist', 1895).
The
Brusden White ACSC Australian Postal Stationery Catalogue provides a comprehensively illustrated and priced listing of postal stationery from 1911-1966 (484 A4 pages!) which is (as you mention) after the issue of your lettercard.
You may be able to find a copy of the Queensland section of the Higgins and Gage World Postal Stationery catalogue but the information will be brief and the prices well out of date.