Hi Lola, I had a look for Jeffrey Birt on the National Archives site www.naa.gov.au and found the following:- Birt Jeffrey Robert Service No: NX9114 Born 17 Sept 1914 Melbourne, enlisted Paddington NSW, next of kin Birt Ruby. It may be worth your while applying for this service record as it may have his address post 1957 if he was entitled to a Service pension.
Regards Peter Dowling