Sven August Swensen, Orphan Born 15 May 1894

Hello, I am trying to find out any information that I can about my Paternal Grandfather who supposedly Jumped Ship, (so the family story goes), in Port Pirie South Australia in around 1907 or 1908. No one in the family knows anything about his history and he has at various times called himself Svendt, Sven, or even Swend Swensen, (the last name never changed), He always told people in the family that he was an orphan, and had no family back in Norway. We have no way of knowing if this is true. His birth date is 15 May 1894, (listed on his Australian Army WW1 and WW2 enlistment paperwork). His birthplace is variously recorded on different Australian Army Documents as being Hilden, Fredrickshald, or Halden. He would have only been 17 or 18 years old when he came to Australia. His occupation at the time was listed as Seaman. He is an enigma to our family, speaking several languages fluently. During his life in Australia he worked as everything from a Labourer, through seaman, to Ships Captain and also he was a Lighthouse keeper and Customs Searcher. He also managed to serve in the Australian Army during both WW1 and WW2. We are at a dead end and can find nothing out. HELP! Thank You. John Swensen