Hi Veronica,
I see that you have a number of certificates attached to your tree, but do you have any which give Christopher's occupation? That is the most important bit of information to try and work out who he was.
Do you have the inquest number for Eva to check if the papers have survived? You would have to be very lucky as only a few were retained, but you never know.
http://www.records.nsw.gov.au/state-archives/guides-and-find...