Found only one record for Sylvanus , look on site "Trove" , National Library of Australia , Australian Newspapers , FREE.
It is a story of his return to his home in Plainfield N.J., to his father Zebbens (?) Compton , Sylvanus had been missing for 19 years and presumed dead.
It is a long story how he disappeared and ended up in the Cape Colony (South Africa) where he married and had one child. From there he went to India , parts of Asia and on to Australia.
This story was dated October 8, 1881 and was in the Newspaper the Newcastle Morning Herald. Newcastle is the second largest city in the state of New South Wales, behind the capital , Sydney. It may be it is in this particular newspaper as he spent time in the area, but I can find no evidence of this.
I searched Trove for S Compton , S H Compton and just Compton, but could not find anything else.
There is no related birth, death or marriage in the State of N.S.W.
On LDS IGI there is a submitted Family Tree showing father Zebulon and 7 siblings. There is also the Military record showing him joining the US Navy in 1863 aged 21 , born Union NJ.