No offence, but I get a bit worried when guesswork is blended with fact.
I have just got a transcript of the marriage certificate of Robert Purvines and Caroline Price.Their parents are not recorded, and neither is Robert's middle name.
In my ancestor Matilda Gordon (nee Purvines) obituary notice (Bathurst Daily Times 14.03.1898), it states "The late Robert Purvines was a brother".Robert Purvines was the son of Thomas Purvines and Martha/Matilda Kilpatrick, who remained in Ireland: that's why there is no shipping record for them.
I have no other "Robert Purvines" or "Robert Gordon Purvines" in my research.That is not to say he doesn't exist, but I would need to know where to look for him, if you could supply that information.
To explain the relationship, I am descended thusly:
David Gordon m Matilda Purvines 1846 Ireland. David Gordon (jnr) m Margaret Flanagan 1879 Bathurst. Robert Edric Gordon (188301925) m Sarah Susannah Short 1903 Bathurst. Douglas Roy Gordon (1905-1984) m Zena Agnes Nicholls 1929 Bathurst. Douglas Thomas Gordon (1930-2000)m Patricia Jean Holt 1952 Kogarah. Mark Thomas Gordon (b 1954).
Thanks for your "Damaris" information - very fascinating! Regards