Theodore Young Kellett - by: Ilze Nel

I ma currently doing my Masters Degree on Genealogy. I am looking for all information on my Great-Grandfather, Theodore Young Kellett. I noticed a document for him on your site called Attested: Jan 1895. Source: CMP 26. Where would I be able to find this source as it would obviously be of great help to me.
Also, anybody know where I can get his UK military records? He came to South Africa from Ireland to fight in the Boer War but also later served in WW1 and WW2 according to his handwritten notes.
Can anybody help please?
Thanks!
Ilze