You can purchase certificates and for $17.50 & download his death certificate directly to your PC, the certificate will list his wife and any children he had. If any. The informant usually has an address listed as well.
From here: https://online.justice.vic.gov.au/bdm/index-search?action=pu...
You will need to use the information from his death index:
Digger - Death Index. Victoria 1921-1985
Given Names: Thomas
Mother: Grace LITTLE
Death Place: FRAN
Reg Number: 516