Thank you very much, Elmarie! Having located 'New Machavie' and seeing that it is in the 'area of interest' given what I knew about the disposition of at least part of the Kimberley Mounted Corps, I am pretty much satisfied that 'Matjavis' is Machavie. I can imagine that somewhere along the line an action or correspondents report was read out over a telephone and the unfamiliar name was misheard.
Anyway, sounds entirely plausible to me, Elmarie, so thank you.
Best wishes, Malcolm
Arthur joined the Colonial Scouts 9 December 1899 in Pietermaritzburg. Like many in the Scouts he served in the relief of Ladysmith before being discharged 15 March 1900. He earned the Relief of Ladysmith clasp. This diary by another member of the Colonial Scouts will fill in some of the detail of the work of the Scouts:
He was likely issued with a QSA with clasp RoL by the Colonial Scouts.
He joined the Kimberley Light Horse and served in the relief of Mafeking and in the OFS and Transvaal. A medal was issued to him by the KLH but returned to the authorities (presumably unclaimed). His initial is E on the KLH roll.
I am not sure where that place is. Stirling, describing the work of the Kimberley Mounted Corps, says: On 7th August  and for some days thereafter a portion of the corps was in contact with De Wet's forces when these broke across the Vaal. At this time a portion of the corps was employed about the Kimberley - Mafeking line, and a squadron was with Lord Erroll in the Western Transvaal in August and September.
There are no enrolment papers for the Colonial Scouts in W0126 but there are papers for the KLH in WO126/74-75.
Many thanks, David,
I have found a transcript from WO100/255 on 'Find My Past' for Arthur and it does state he was entitled to the QSA with clasps for RoM, OFS and the Transvaal.
Not having given a lot of thought to the Boer War previously, I find I am getting more and more interested in this conflict, and this forum is just the place to ask for help in understanding it.
This could be where your man was in August 1900. The map shows key railways and stations along the line.
If you do get the Boer War bug, this is certainly the place to enrich your ABW knowledge.
You only live once, but if you do it right, once is enough.
Quick Update - Have found an 'A Ringrow' in the shipping records on FMP traveling from Southampton to Capetown on the 4th November on the steamship 'Briton', arriving there on the 20th. David (djb) has written that Arthur joined the Colonial Scouts 9 December 1899 in Pietermaritzburg, so it appears that he wasn't a settler as I had previously imagined.
Much appreciated, Dave F!
I'm happy in my own mind that Machavie is where our Arthur met his end. I'm still intrigued though as to how and why he went to S. Africa. I've located him in the UK census' for 1871, 1881 and 1891 as someone from a relatively well-off family who became a reasonably well off farmer. (I don't know the sums involved yet but I know he has an entry in the Death Duties Register).
I haven't found any South Africa connection yet so I don't understand motivated him to go as a civilian. Perhaps he intended to settle there after he had 'done his bit' for Queen and Country? Anyway, thanks again for your interest and help.