"they had taken no steps to procure such maps as existed".
Entry no.179 MAPS, is a work in progress, and as regards Lasseter's maps some might claim this state of affairs has existed for the last 85 years, there is a great deal to be written about Lasseter and his maps, meanwhile another small mystery has been cleared up thanks to the State Library of NSW. In his book, "On Lasseter's Trail", (1989) Desmond R. Clacherty suggested that Lasseter had used a map published in 1827 as his guide across Australia, Clacherty does not reference this map and heavily modifies the original from Thomas J. Maslen's book, "The Friend of Australia" (1827).
On Lasseter's Trail, Desmond R. Clacherty,1989 pgs 45-51.
Maslen's Map, the Friend of Australia, Thomas J. Maslen, (1827) State Library N. S. W. http://www.sl.nsw.gov.au/discover_collections/history_nation/exploration/maslen/maslen.html