Thank you both.

In the book 'Old-Fashioned Gardens' by Trevor Nottle, (1992, Kangaroo Press, viewable online) on page 158 is the following entry under 'Squatter's Dream':

"Squatter’s Dream (1923) A rose bred in Australia by Alister Clark and propagated from plants found growing, complete with labels still attached and legible, at Old Anlaby homestead, near Kapunda in South Australia. The bushes are spreading and covered in dense dark green foliage that is glossy and disease resistant. Masses of single yellow and old gold flowers bloom early and late on a plant that is everblooming in warm areas."

So the original bushes at Anlaby were labelled? This should put any doubts about 'Squatter's Dream' being correct to rest. What seems a little odd to me is that this book was published in 1992, yet the 1995 reference here of how Nottle came across the rose mentions no labels and that would obviously be a crucial factor in identifying the rose. I know from the Tea Rose book that the Anlaby garden was big on labels so it's very plausible that old metal labels were found marking the old bushes, but it just seems odd that this is the sole reference to labels.