I tend to agree that BSA selected a lot of their wood from the military production line
especially for this model which is the #4 sporting carbine.
The butt looks correct to me and should be of military profile with checkering.
If it has a sheet steel buttplate without a trap and a single screw sling swivel then
it would date from 1904/5 yet the SMLE Mk.1 did not have a charger bridge.
That cutout is a bit of a puzzle which can only date from 1907.