Long Branch No4 T snipers appear to have had the Rings (partially at least) numbered right from "day 1".
My understanding is that the instruction to number the rings of British No4 T rifles was issued in 1946 or '47, but the British "List of Changes" and contract instructions are well known for issuing retroactive instructions.
My belief, based on observation and limited experience is that by mid- 1944 H&H was numbering rings (on their own hook) and the ACI/List of Changes instruction to do so was issued retroactively post war.
Does anyone (Roger/Lance/Rob ??) Have a late MkII, MkII/I or Mk3 scope in its original bracket which is not numbered?
As to the magazines, most (but not all) No4T mags (which appear to be original to the gun) which I've observed are numbered - but again, this is a replaceable part.