So, I've sourced those two documents from the Cape archives and have transcribed these to the best of my ability. Both documents were addressed to J. Gordon Sprigg, Colonial Secretary, at Cape Town.
In the document dated 06/04/1878 re: non-receipt of rations at Komgha, he signs his name as J. Corrie, Field-Commt. He mentions, as witnesses to the truth of what he has stated in this document, Major (Hans?) Moore and a Mr. Grant.
In the document dated 14/05/1878 re: reporting patrol at Kubusie, he signs his name as J. Corrie, Captain. In this document he details how they followed some rebels, killed five and repatriated some livestock. This document is important as he refers to Lieut. Cowie i.e. Corrie and Cowie are NOT the same person.
I've also found in a list of names of Officers of the Kaffrarian Volunteers:
List of Officers, Kaffrarian Volunteers
Captain Commandant James Faunce Lonsdale 22/2/1872 (Note 1)
Captain R. Walker 1.3.1875 Mounted Troop, KWT Volunteers
2/Lt A. Duncan 1.3.1875
1st Lt C. Musgrave 1.3.1875
Lt E. J. Byrne 22.2.1872 No 1 Company KWT Volunteers
Lt G. V. Perks 22.2.1872
Capt T. W. Robertson 15.12.1874 No 2 Company KWT Volunteers
2/Lt R. McWilliams 15.12.1874
Capt G. Grey 1.7.1875 Gonubie Troop
Lt W. Warren 1.7.I875
2/Lt R.J.Dick* 1.7.1875
Capt James Sansom* 18.11.1872 Komgha Troop
LtJohn Cowie 18.11.1872
2/Lt T. Curtis 8.4.1876
Capt Howard Sprigg 25.11.1876 ***Brother of J. Gordon Sprigg***
Lt G. Impey 20.7.1877 Maclean Troop
2/LtT. H. Stokes 25.11.1876
The list makes no mention of my Captain Corrie. I have however found in the Frontier War Journal of Major John Crealock reference to a telegram from General Thesiger to the Cape Governer mentioning "From Komgha a patrol under Captain Corrie followed a party of rebels, recaptured all the stock taken and killed five". Which is a despatch about the second document, as listed above, for which I have Captain Corrie's first hand account (that which I could transcribe).
So I beg you courteous, and scholarly gentlemen might assist me in identifying my Captain J. Corrie of Komgha, Kubusie, Stutterheim etc.