Brian, thanks for your help deciphering. (It's a joy to have a Sherlock Holmes on my team.) Here's what I found on the Knox:
- matching serial number
- broad arrow
- N17(under crown) [does this mean pre-1954 import?]
- F5 [??]
- M(over)3 [Albion Pressed Steel Metal Co. Birmingham??]
- no "BNP" nor "England" stamps
- no "CG" or "SA" [South Africa] markings anywhere
Back to the Forend: Draws fit tight and true, but no serial number on top which might validate your replacement wood hypothesis.
So: some of the evolution of the gun may remain a mystery.
And someday we may find out the real reason why some 1944 Maltby Enfields get a "*" Star Rating.
P.S. I'll be back to you late next week via PM on the restoration of the LB Sniper