Hi Philip, nice to hear from you.
I remember that I was contacted by I think by a Cox who lived in the Wollongong area, it must be at least 5 or 6 years, regarding the Cox family. the chap's father was James Joseph son of Henry John Cox and Suzannah who lived in Bowraville.
The information you have appears to be the same as I have ,only difference is that Henry John's grandfather was named John Williams Cox. Also I have been unable to establish when John Williams Cox wife Charlotte died in London, or when Henry the son of John Williams Cox arrived in Australia. It must have been sometime between 1841 and 1858, John Williams Cox arrived in 1841 and Henry married Mary Jane Keenan in 1858.
Good luck with your search, I have not done much on the Cox family for years, as I came to a lot of dead ends. If you think I can help with anything send me a PM with your email address
Regards
Cass