Hello
If I may chip in - they do say there is a web forum for everything and maybe there will be some people here who could help with your research 1879zuluwar.talk-forums.com/forum.htm. It seems it is a discussion and reference forum.
Would love to know what you find out about your chap 
Good hunting
Lorraine.
I Have been to that forum and found out this.
Thomas Henry Anstey
He served with Newdigate’s division in the advance from Koppie Allein, and was present at the Battle of Ulundi. Subsequently made a triangulation survey of the route taken by the division from Landman’s Drift to Entonjaneni. On his return to Maritzburg he was ordered to survey in detail the Battle-Field of Isandhlwana and the ground adjacent thereto.
Date of Birth:- 23rd September 1841
First Appointment :- Lieutenant Royal Engineers 25th June 1862
Captain Royal Engineers 12th August 1875
Major Royal Engineers 25th June 1882
South African War:- 1879 - Zulu Campaign - Battle of Ulundi. Medal with Clasp.
Source ‘1884 Army List’ (p 298, 783 & 1208)
Lieutenant Colonel - 11th June 1889
Army Rank: Colonel 6th January 1894
War Service - South Africa 1879. Retired 1896.
Also about Browndown rifle meeting
BROWNDOWN RIFLE MEETING.
HC Deb 15 June 1893 vol 13 c1050 1050
ADMIRAL FIELD (Sussex, Eastbourne)
I beg to ask the Secretary of State for War whether it is true, as reported, that the War Office authorities have refused to allow service ammunition to be issued free for the usual annual naval and military prize competition at Browndown, held under the patronage of the Naval Commander-in-Chief and the General commanding the Southern District; whether it is a fact that for many years past ammunition has always been granted as an encouragement to both Services to acquire proficiency in the art of shooting at these annual prize meetings; and whether, seeing that the officers mainly provide the prizes, he will direct that the necessary ammunition be supplied in the interest of the Public Service?
THE SECRETARY OF STATE FOR WAR (Mr. CAMPBELL-BANNERMAN,) Stirling, &c.
I am informed that ammunition was refused for the Browndown Rifle Meeting this year because a large excess of ammunition issued for this purpose in previous years was struck off at the request of the General Officer commanding the district, on the ground that these meetings would not be held in future, the organisation under which they had been held having been broken up, and there being no person left in the district who could be held responsible. Of course, I can only speak with regard to the Army.
In the same forum is also a picture of him and a picture of his daughter
Found this on an antique site
leopardantiques.com/object/stock/detail/121
The same shape as mine altough the looks are not the same. Maybe this model was populair among the military?