Hi ciroferrara
If you are researching Durnford, and assuming you haven't already, you might like to consider buying/borrowing "The Road to Isandhlwana - Colonel Anthony Durnford in Natal and Zululand" by R W F Droogleever (Greenhill Books London 1992 ISBN 1- 85367-118 - 5). There are a number of (black and white) photographs - both contemporary and more up to date - of the Bushman's River Pass. In the footnotes to his latest book, Zulu Rising, Ian Knight describes Droogleever's book as, "By far the most perceptive study of Anthony Durnford's life and career"; I certainly enjoyed it.
Hope this helps.
U