I wonder if you've come across any info about two other Henleys who also emigrated to NZ in 1874-6. I don't think either of them is closely related to your Thomas Henley.
(1) My gg-uncle John HENLEY born 1844, Tailor of Brighton, Sussex, wife Clara Jane 25, daughters Lillian 4 yrs, Clarice 4 mths migrated to New Zealand on the “Hereford” (sailed 17 Apr 1874 arrived Lyttelton 14 Jul 1874). They settled in Christchurch and had at least 6 more children. Neither of their two sons reached adulthood but 5 of their daughters married (more info on
http://www.cousinconnect.com/d/a/98087). I have no information on any of their descendants. John died 9/9/1897 and was buried at Linwood cemetery, Christchurch.
(2) Another unrelated John Henley born 1843, also a Tailor of Brighton, Sussex with his wife Amy 32, dau. Clara 11, migrated on the “Rangitiki” (sailed 14 Dec 1875 arrived Lyttelton 14 Feb 1876). I don't know where they lived, or whether they had any more children, but by 1894 he was listed as a missing person in the Salvation Army 'war Cry', and he died 21/10/1900, buried at Waipukurau.
- Stephen Henley