This looks like him. His death certificate should tell you details of any marriages, how long he had been in Victoria and other colonies and a lot of other useful stuff.
Digger - Death Index. Victoria 1921-1985
Given Names: David Valentine
Mother: Jeanie VALENTINE
Death Place: BALW
Reg Number: 24091
This is the record of this man's cremation. http://deceasedsearch.com/page-o6986454-en.html
If you click on the location of the ashes it shows the ashes of another person at the location - possibly a wife.