Hi Julie , most likely IOM to Liverpool and then Liverpool to Melbourne . Only about 10% of ships came to Aus from Liverpool in the 1850's
most from London and/or Plymouth and to a lesser degree London/Southampton . As I pointed out I could not find any Edwin arriving in Australia at that time , and the John's I gave you were the only possible / close to the correct age . You should go to the state archives in Melbourne , where you could track down the family and details of where they came from and where the ship sailed from

Regards
David