Daowlis & Matarangas Surnames

Can anyone help me? My grandfather was named Michael Daowlis, born 1883 at Kalamatta in Greece. He married in Sydney in 1930 and died at Newcastle in 1938. According to his death certificate his parents names were John, a ships captain & Mary Lavaraga who were dead by 1938. I think the difficulties in learning anymore about his life and how he came to Australia lies in the anglicized surname. Can anyone guide me to what his Greek spelt surname would have been?

Number two problem I have is researching my step grandfather (who apparently was a best friend of my grandfather named above. PIERRE DIONYSSE MATARANGAS married my grandmother in 1942 in Newcastle, NSW and was a cook at Jerrys Cafe on the waterfront. According to his death certificate he came to Australia about 1908 and served in the Greek war against the Turks. Once again any assistance in finding any info on him would be most gratefully appreciated