Not much help in finding John/Michael, however some hints which may help you find the birthplace of Catherine.
Posting these for our interest as they would appear to belong to your family:
Deaths, Victoria
Mark Austin CLERY, 85
Died at Sbla, Victoria
1984 #00609
Father's Name: Charles
Mother's Name: Catherine
Catherine Clery, 82
Died at; St Kilda, Victoria
1955, #8514
Father's Name: Austin
This lady's death date gives an approximate birth date of 1873 which may help find her birth.
There are also some index entries for births of children of Charles and Catherine which should give her birthplace.
Did the Michael CLERY that you are looking for ever come to Australia?
Judith