... and that Thomas's mother was Mary Ann Bartin not Barton as the transcript said?
Hiya tartanpixie
I'm not sure how much emphasis should be placed on the spelling of Mary's name, especially as her daughter's name is written as
Helin on the same slave return (below) — likely to be a phonetically-challenged clerk, do you think?
I'm pretty sure that I would have found Mary BARTIN or her
St HILL children if they'd ever got as far as NZ. I've certainly found not even a vague hint of them in NZ or Oz newspapers, BDMs, etc.
The only NZ reference I can find to Bradninch is in a biography for James Henry St HILL which I think you (or was it Kathy?) sent a couple of years ago, where it says, "He was the son of Henry Charles St Hill, of Bradninch, Devonshire, who served many years in the British ordnance department, mainly in the West Indies, Ceylon and Hongkong, retired and died at Wellington on 12 Mar 1861." Unfortunately I haven't a clue what publication this biography came from (a scan from a book) but it cites C. H. St Hill (Rev Harry's son) as a source.
In Henry Charles' will, even he doesn't say he is 'of' anywhere. It seems to be Ammabel who liked to tie her husband's
St Hill family to Bradninch at every opportunity!
(cf. below from de Ruvigny's Roll of Honour)
Hello Katrina
Would be great if you could ask around.

Some of what Ammabel would have documented was destroyed in WWII, eg. Devon wills and administrations were lost when the Exeter Probate Registry was bombed in 1942.
Do you know where your great grandfather got the name Collis from? He didn't use it when he signed the parish register at his marriage — perhaps it was a family nickname?
I wish you both a Happy Christmas and all the very best for the New Year.
Koromo

PS. Windle Hill St HILL also liked to refer to Bradninch:
Australia newspaper archive