Just for your information some of Wilkinson-Latham's captions are off the mark especially on that page.
For example the top photograph are not N.N.C., but are actually the White Rock Border Guard.
I have a copy of the lower photograph was is annotated 'John Dunn's Men'.
I also have photograph on page 70, but it does not indicate the regiment of N.N.C. However, I'll examine tonight after work as I may have spotted something.
I will notify my SAPS friends when you are due to visit the Local History Museum on Frank's advice...