Welcome to the Forum. The Identification discs you show are of the type issued to British and Empire troops during WW1. They were made from compressed fibreboard. There were no official ID discs issued during the Boer War. Personal details were recorded on a panel sewn into the tunic - or else on a slip of paper intended to be carried in the pocket. I am sure that a search on-line would tell you more about what the various letters stamped on your GF's ID discs mean.
By the way, the term "dog tags" is of American derivation and dates from WW2.
If you can supply us with more details of your GF, one or other Forum members may be able to assist finding any Boer War service.
Good luck with your quest
Thank you so much for answering so promptly.
My grandfather's full name was Albert Edward Stoneham. His year of birth was 1881 and he lived in London as of 1911 - I am not sure if he was in London prior to that.
I understood that he was injured in the Boer War - that was what I was told by both grandparents and my Mum and Dad when I was growing up.
Any added information would be lovely.