Hi tascj,
I do think that it most likely he used the name FALKINER during his radio days before coming to Australia.
To get a job in radio in Melbourne he must have needed references to describe his experience and these would obviously have to correspond to the name under which he applied for the Melbourne position.
Therefore, somewhere there has to be a record of this man of some kind

My other thought is the possible reason the word "married" is on the immigration card.
The children had been registered under false information i.e.that the parents had married in 1947.
Like you, I think he probably was their father and, in order to maintain the lie on his entry to Aust in
EDIT 195
4 7, he stated married (meaning to Mabel).
Sue