"So given the 1894 date this would have been on MLM carbine? I thought the non carbines MLM did not have ID disks because they have the longer butt plate tang."
As far as I am aware: The LMC (Lee Metford Carbine) and LEC (Lee Enfield Carbine) were used only by Cavalry - not used by Artillery. The carbine used to defend Guns would have been, from 1888 - 1896, the MMAC (Martini Metford Artillery Carbine) or, after 1896, MEAC (Martini Enfield Artillery Carbine); both of these bore stock discs. I have photos of the heavy artillery at Colenso (Dec 1899) manoevering their Guns into position with MEACs slung over their backs. Thus I suspect your 1894 disc would originally have been found in the buttstock of an MMAC. I could be wrong, but that is how I understand it.
TerryLee, who has examples of all these in his collection, would be better placed to confirm or correct this.
Rob