Hi Jack
The National Archives in Pretoria have the following documents, a researcher as listed on this site could get it for you
Regards
Adrian
Johannesburg
:
DEPOT     TAB
SOURCE    SAC
TYPE      LEER
VOLUME_NO 66
SYSTEM    01
REFERENCE B1006
PART      1
DESCRIPTION          RECORD OF CONDUCT AND SERVICE OF SOUTH AFRICAN CONSTABULARY EDGAR
ETCHES.
STARTING  1900
ENDING    1905