The NSW government has aerial images of Sydney that were taken during WW2 in 1943 at
http://maps.six.nsw.gov.au/
The attached image shows a vacant block in 1943 where Dunlop made his two catalogues of 253 Double Stars and 629 Clusters and Nebulae in 1826.
The attached map shows part of Parramatta in 1823.
D marks the location of Dunlop's house.