When asking for help it is a good idea to provide the information you already have to save helpers having to search for stuff you already have.
Considering you are after a birth,,providing his age at death and parents names are of the utmost importance..
Do you have his death certificate?
It should state his wife/childrens names and his time in Australia.
His death registration
Name: Hy Page Saunders
Death Place: Bendigo, Victoria
Father's Name: Wm Carne Saunders
Mother's Name: Ann Carne
Registration Year: 1900
Registration Place: Victoria
Registration number: 7960
Estimated Birth Year: abt 1819
I assume this is his marriage
Name: Henry Page Saunders
Spouse: Elizabeth Luxton
Marriage: 1856 - Victoria
so we know he arrived by 1856..
Do you have this marriage certificate?
It may name his parents or if he had been married previously. Also his death registration seems to have odd parent details.
This arrival is a pretty close match
SAUNDERS HENRY 45 FEB 1853 CLARA SYMES B 029 009
SAUNDERS WILLIAM 18 FEB 1853 CLARA SYMES B 029 009