I looked at the Australian Electoral rolls, searching for either Maurice Alan Condon or Maurice Conrad Condon.
Earliest that I noticed was for 1937:
Maurice Alan Condon at Corio Victoria Altona Williamstown racecourse Student.
But here is a shock!
1942 Corio Victoria Altona
Maurice Alan Condon Blyth St. Geologist.
...And next to him on this census is:
Maurice Conrad Condon Racecourse Williamstown Gardener
So this proves that they are two different people.
Maurice Alan Condon is still at Blyth St in 1949 and still a geologist, and Maurice Conrad Gordon is still at Racecourse, North Williamstown, a gardener.
Then in 1954 Maurice Alan Condon is at Australian Capital Territory: The Territory for the Seat of Government
It reads: Maurice Alan Condon 57 Boldrewood St Turner, Geologist. And in the same house is: Saxon Marjorie Condon Home Duties.
1958 Both at same address. Same 1963. Same 1968.
Then in 1980, both are at NSW Lyne Tinonee Bohnk.
Maurice is now a Manager.
Maurice Alan Condon was a Geologist, whereas Maurice Conrad Condon was a Gardener. If it says on the 1941 marriage certificate to whether Maurice is a Geologist or Gardener this would identify which of the two Maurice's he is.
P.S. Maurice Alan Condon made a trip to San Francisco on 14 Aug 1956. Left from Sydney on Qantas Empire Airways.
According to a Ancestry, he was going to Honolulu.