Your uncle's two page Royal Australian Naval Reserve Record of Mobilized Service is available on-line at the web site of the National Archives of Australia. Just do a search on his service number.
Among other things it says he was born October 18, 1898 in Colerone Ireland and his wife was Irme. He was mobilized on September 2, 1939 and on April 3, 1942 he volunteered to remian with sick members of a naval party evacuated from Rabaul to the south coast of New Britain. He was reported missing afterwards and presumed dead on July 1, 1942.