Firstly, congrats to Dave for his detective work par excellence in finding the paperwork covering James William's military service in South Africa, Ceylon & India - it defeated me and presumably he went from SA to Ceylon escorting Boer PoWs.
Secondly he was not entirely truthful when he attested for service in the KRRC in August 1899 as this set of paperwork indicates he had previously served in the 3rd (Militia) Battalion KOYLI for a month in 1896. It also tells you which colliery he worked at.
Thirdly, he had a younger brother named John who attested for Militia service in the Yorks & Lancaster Regiment in February 1896 but on 9th August 1899 (the same day James William attested) was transferred to the KRRC. Here is the paperwork and note the address he gave which is identical to that James William gave for his father.
Fourthly John does seem to have qualified for the KSA but I cannot find any service records covering his time in SA.
Finally, I need to find some paracetamol as I have a headache. PS a Public Family Tree on Ancestry has James William and his brother John on plus a lot more siblings.