My fault for not clarifying- it is currently wearing its original 5-groove enfield barrel as it was born with. The spare martini metford barrel that was thrown in with the deal is only being scavenged for its intact front sight.
You are correct in that no carbines were being produced after the enfield was adopted-for military use. Carbines were still being offered commercially for some time after the adoption of the MLE as standard. Metford barrels were still being offered well into the 20's, as target shooters thought them superior for target work.
I remember reading in one of my Boer-War books (either Pakenham or Lee) officers did indeed carry rifles in that conflict. They also dropped the wearing of the riding breeches as the cut of the pants and the carrying of carbines marked them as officers. Sharp-eyed Boers looked for these characteristics when selecting their targets. By the wars end, the officers looked very much like the regular infantryman, distinguished only by rank insignia.
Bubba: he comes in all shapes, sizes, and ages. Last year I was at my local range shooting a No4T. On the bench next to me was this 16-year old kid shooting a Rem 700 6.5 Creedmore. His rifle was extremely accurate. He saw my targets; 1.75 to 2.5 inch groups at 100 yards. He then proceeded to lecture to me about glass-bedding the action and free-floating the barrel. He also suggested cutting the wood down and ditching handguards, as they are "bad for accuracy." Nice enough kid, but uninformed. I politely declined his advice...