Well Neil, I too would have thought George Richard McIntosh a person of interest and worthy of further investigation. But, can't win them all, I guess.
George Richard's grandfather came to Australia in 1853 with wife and daughter on the
Tasmania.
They are included on the Mackintosh Families of Australia website -
http://mackintosh.org.auHe started the family line referred to as Collingwood2 which has 137 members.
The website is a great resource for people related to McIntosh's. There are now over 45,000 individuals listed - including moi

Unfortunately the person that the OP is after is not included, probably due to his more recent arrival.
But your friends from NZ might be there, especially if they have links with Aust.
Keep up the good work. I enjoy reading your posts.
Spike