I have some thoughts to share.
http://trove.nla.gov.au/newspaper/article/13032865 SMH 8 Nov 1859
£50 reward offered for Thomas PECKHAM, in respect of the murder of John MOORE, 4 October near Camden.
NSW BDM online index has that 4 Oct 1859 death for John MOORE, with his parents given names as John and Mary.
NSW State Records do not have the Inquest reports for that era, only the index. The files are likely no longer extant. I have not searched trove for any reports of the inquest. But may I mention that "native" in that era refers to a person born in New South Wales, and so the Thomas Peckham who is named in that Nov 1859 cutting is someone born in NSW whose complexion is dark .... so perhaps someone who had spent most of his life working outdoors.
John MOORE married Susan CATERSON in January 1856. The NSW BDM commenced civil registrations in March 1856, so may I comment that the NSW BDM record of that January 1856 marriage may be scant on information, but hopefully the original parish register (St Johns Roman Catholic church, Campbelltown NSW) may contain further information that John gave the clergy about himself. (… perhaps some or all of the following clues: age, place of birth, ship of arrival, occupation, father’s name/occupation). As divorce did not come to NSW until 1873, that 1856 marriage record would give John’s status either as widow/er or as bachelor. He was not a young man when he married Susan, was there an earlier marriage perhaps.
May I ask if you have searched for the original register of that marriage, to see all the information that may have been recorded there. ….. not the summary information that NSW BDM may hold …. I am hoping the clergyman was aware of the requirements that were to commence from 1 March 1856 and may have asked John MOORE for all those, or alternatively may have asked for and recorded the name of his ship of arrival …..
Otherwise, I cannot actually see how you can join the dots back to the chap on the Mangles over twenty years earlier. There’s many chaps in NSW in the 1850s clearly named John MOORE, probably many of them arrived in the early 1850s chasing their fortunes …. Gold Rushes come to mind.
Here’s the index sightings:
NSW BDM online index
http://www.bdm.nsw.gov.au/Pages/family-history/family-history.aspx Birth registered Camden district in 1860 for Mary, with parents as John and Susan MOORE
#5931
Death registered Camden district in 1859 for John, with parents as John and Mary MOORE #2820
Early Church Records Marriage in 1856 “LE” (St Johns Roman Catholic church, Campbelltown NSW) John MOORE and Susan CATERSON
# Volume 101, line 731
Familysearch.org
https://familysearch.org/ark:/61903/1:1:XTZJ-C8K Susan Caterson marriage 7 Jan 1856.
So, I am concerned that there could be confusion between the various John MOORE chaps in NSW in the 1850s, basically because not all official records have survived, and civil registrations of BDM events did not commence until 1 March 1856.
JM