Petrohelos; family

Hi, I am doing research for the family tree on my wifes relatives, her grandparent's on her father's side were Vasiliou and Jovanna Petrohelos and Arthur and Marietta Pavlakis from Fratsia on her mothers side.Her father George emmigrated to Australia in 1927 and settled in Ipswich Queensland,and was later joined by his brother's Jim,John and Nick.George later changed his surname to Kentrotis.
I would be gratefull!!! for ANY information that would help.
Regard's Mick