Australian Electoral Rolls
1919
MITCHELL Flora McLeod
609 Ascot Street south, Ballarat HD
MITCHELL Robert
609 Ascot Street south, Ballarat Labourer
1924
MITCHELL Flora McLeod 37 Magpie Street, Ballarat East HD
MITCHELL Robert 37 Magpie Street, Ballarat East Carpenter
1931, 1936
MITCHELL Flora McLeod 187A Barkly Street, Ballarat East HD
MITCHELL Robert 187A Barkly Street, Ballarat East HD
1937, 1949, 1954
MITCHELL Flora McLeod 185 Barkly Street, Ballarat East HD
MITCHELL Robert 195 Barkly Street, Ballarat East Carpenter
There are two service records on the NAA website for Robert MITCHELL with NOK Flora, and one states his dob is 26 January, 1890 Kent, England.
The link given by Sue has unfortunately, timed out.
http://www.naa.gov.au/collection/recordsearch/index.aspx>Search now as guest user
>Use Robert Mitchell Flora as keywords to search.
One of the records has been digitised.
My comment on the dates stamped of the letter from the Repatriation Department to Army records would be that the date stamps of personnel who processed the letter. There is no actual date on the letter from the Repat. Unfortunately there is no indication of the date Robert applied to the Repatriation Dept. Just a thought, I wonder if assistance was sought for funeral costs

Births in Victoria are only available to 1920.
I will pm further information.
Cheers
Cando