Dazzles on Family Tree Circles

My great Uncle ROBERT WILLIAM CHESTERFIELD was born in Baddiginni Victoria in 1885. He moved to Beaudesert Queensland with his parents and two brothers in 1892. After his mother died in 1906 he moved to Victoria and joined the Navy in 1907. He met Mary Caroline Saunderson in Tasmania and they were married 24 February 1911 in Hobart. She had an illegitimate son Charles Saunderson born in 1904. On 23 February 1916 Robert enlisted in the AIF in Goulburn NSW. His address at this time was Colo Vale NSW and his next of kin was his brother George. During the War, his wife lodged a claim for maintenance for herself and her son Charles. She told the Army that he had abandoned her and could be using another name e.g. his mother's maiden name "Curran". This was acknowledged by the War Effort and his wife was sent money from his wages and she was then listed as his next of kin. After serving overseas, Robert returned to Australia in July 1919 and returned to his Naval position as far as we know. His younger brother (my grandfather) would have nothing to do with him when he found out he had left his wife in Tasmania. The story goes that he met another woman and had a few daughters to her but was never married. All attempts to find his death have failed. However, he was last heard of living in Maryborough Victoria quite some time ago. We have not been able to find his name on electoral rolls. Could anyone let me know if you know what happened to him.