Hi Michael
The bike on the right I am pretty sure is a Bradbury, pre 1912. The frame tubes joining straight to the crankcase is the giveaway - and the tank transfer certainly looks like Bradbury. The one on the left has a water cooled engine and I would think is a Lewis - made in Adelaide. They typically used water-cooled Precision engines. Also pre 1912, judging by the straight top frame tube.
Cheers, Graeme