Thanks to everyone for your replies and suggestions.
I have to confess to a bad mistake in my original post - quoting George's parents from his marriage cert as PETER and Maude Hunter when it should have read STEPHAN and Maude Hunter. My humble apologies
The Peter Hunter a baker in Masterton mentioned by majm is my 2x gt uncle. He married Alice Mary Sutton in 1881 and they had nine children - but no George. One of their children was the Maud Winifred Hunter b. 1887 Masterton mentioned in reply#9 from majm.
The George Hunter at Masterton 1905-6 I cannot place but from the ER it looks as though he could be married to a Mary Hunter, married, also residing at Colombo Rd.
Re the online tree mentioned by majm in reply#9.
Many Thanks for that, but it seems to be a good example of the problem with online trees mentioned by Ruskie.
Re George's Mum. The only Maude Hunter death in NZ between 1880 and 1910 was a Maude Lillian Hunter who died aged 6 months!
The birth in Brisbane 1885 is more interesting because I have a 1st cousin 3x removed a William Hunter who I believe died 20 Jan 1922 Melbourne, Victoria. I cannot find any marriage to a Jane Ellis for him though, but if he was the father of George the buffalo hunter it would explain the DNA result.
Other details from that tree seem to agree with what I've been told, so thanks to majm for that confirmation and links.
I'll add a link to this thread on the NZ board - thanks for the suggestion Jamjar.
John B