I'm one of your cousins in Australia and have a few more details ...
The Edward who moved to Australia was Edward John Dowley (courtesy of the Fairbridge Society I believe) went to Victoria initially in 1924 and then on to Western Australia, which is where he settled.He then married Rosalie Joan Couper in 1939.His three children were Edward Bevan (Ted - your dad!), Graham Stephen (my dad!) and Bernard Francis (Bernie).
Our grandad Edward John was born in Southend-on-Sea, Essex on 21 March 1911.My parents have his birth & marriage certificates.He died on 12 February 1995.
His parents were Edward Stephen Dowley and Louisa Mary Corcoran (formerly Davies, nee Corcoran - she had been married and widowed).They were married on 10 July 1906 in the Register Office in the District of Croydon, London.
The children of Edward Stephen Dowley that I'm aware of are: Dorothy Kimpton, Elsie Goldbrom, Edward John (3rd) and Jim (6th).We understand that one other brother died during WW2.
We gather that another brother (Fred?) may have moved to Australia (Queensland?) at a similar time to Edward John Dowley.He could be difficult to identify because Fairbridge Society and their ilk frequently changed names & birth dates to make it difficult for them to trace their families.
I'm in the process of getting some more details from my parents & will get in touch later.