Marvellous photograph ... love the top hats!
Probably c. 1860/70s. Just see the single driver.
DRAWING OF J CLASS STEAM LOCOMOTIVE c1860 - Public Record Office Victoria wiki.prov.vic.gov.au/index.php/VPRS…
Superb photograph.
J #6 was last of the class scrapped in 1916.
railstory.org/chapter-four/
J is bottom right of this chart. Better in full size follow link.
Victorian Railways Locomotives 1895
State Library of Victoria
handle.slv.vic.gov.au/10381/95769