Have been following your thread with great interest. There are three photos to be found on the web that you may or may not have seen before.
First two are 'copyright Reed Business information'.
Described as a 1909 Dennis with quite extraordinary front wheels (perhaps twice normal width and appear to be rivetted steel – like a road roller?), front axle with U bend, chassis ends same as yours, full frontal shot of the aluminum (?) & horizontal tubed radiator, mounted same as yours. I can’t tell whether it’s 2 or 3 tonne.
Described as a 1910 Dennis, similar chassis, very different radiator, pictured from 45 degree angle to front.
The third photo you will find on the site of the State library of South Australia
Described as c1911 Dennis. This one is similar to b) above.
Regards Robert