All the names you mention are well known here in Melbourne, one correction though, the birth town of all the Failla's you speak of is Licodia Eubea in the province of Catania in Sicily, Italy.
I know several Vincenzo Failla, one from the Emerald area although now he lives closer to downtown in Coburg. he was a potato farmer from Gembrook, he would be about 70 years old now, he is a cousin of my late fathers. The name Croce Failla, is also well known to me as I personally knew him, although he passed away some years ago now, he would have been born on or about 1933 like my father Giuseppe. My father's mothers name was Margherita, although she was a Zappulla. A bit of my family history, my grandad was Paolo, one of seven siblings, he fought in WW1, and migrated to Australia during the big migration boom in the 60's. My father was the first of his family to migrate to Australia, in 1952, and laid the paving blocks that allowed the rest of the clan to come here. He had three brothers Santo (still alive in Licodia although suffering from dementia), Francesco (Ciccio) and Mario, all deceased now.
Anyway I would be pleased to help you trace anyone if you give me more details.
Sebastian (Sam) Failla