Thanks for your interest Canuc.
I do not know whether or not the man (my great grandfather) we are concentrating on is in the large group photo or not.
This group is some of the soldiers of the ( British) 57th Regiment of Foot who were sent to NZ in the 1860's to fight in the NZ Land (Maori) Wars.
My ggf was in that regiment and definitely in the area where the photo was taken, around that time.
The puzzle that I have stems from the date given with the group photo of circa 1864. He was discharged from the regiment in March 1864. If I had a definite date for the photo I could say he was either possibly in it, or definitely not.
The date of the foursome? I'm not entirely certain. The photo gives a date (July,1868), but that is actually the date of the battle in which these four men served. (He joined the Armed Constabulary after his Imperial discharge). I think, from my enquiries, it is likely to be circa 1870. Then, he would've been 35.
I didn't mention previously that his left leg was badly injured in the 1868 battle, after which he often walked with a stick. But I don't think he carried a stick prior to that date.
The Band photo was definitely taken in 1872 (when he was 37 yrs).