Sorry, I must have been dozing not to notice this one...
Here goes:
Rifle is genuine but has been got at:
the forend is early as people have said. It bears the down-cut on the R side for the (redundant cut off). It also has the characteristically early cone shaped machining on the inside of the forend for the front trigger-guard screw. It does bear Faz mark & may be of Faz mfr but I have seen a lot of early LB forends like this.....it's possible that it could have started life there. All of the ones I have have a 'B' (I think within a circle IIRC without looking) on the rear of the forend tie plate; but you'd have to take the forend off to see this. Another thing that makes me wonder if it could have started life in Canada is that the removal of the wood for the bolt release catch looks rather amateurish & done by hand. This would only have occurred if the forend was originally intended for a Mk1* rifle, & was subsequently modified. I may well be wrong on this as the pictures are quite good but handling it in the flesh would make life so much easier....
As an aside early T conversions manufactured by both ROFM & BSA tend to be fitted with beech wood; AFAIK the walnut seems to have come on stream by 1943 & became the norm.
The front body pad looks like a real one but IMHO has been refitted & may well not be the one that originally grew there. Look carefully at the right side profile......it has been got at presumably with a file to put a gradual radius down to the bottom corner....I suspect because it did not quite fit into the existing front pad milling here on the receiver sidewall. The general look of the screws & centre punching also looks to me to be recently done....certainly not from 1946 anyway!
The rear pad, aside from the gap, does not look obviously recently refited to me, but again seeing in the flesh is the ideal.
The batch my friend & I bought in 1997 had been partially stripped as I believe this one had been....we bought a lot, but I gather quite a few that we didn't manage to hoover up went in to The States....
We spent ten years gradually putting rifles back together & I've no doubt we weren't the only ones.
ATB
PS. Mag is scarce but not ultra rare. I have a couple of SMLE mags that appear to have been modified carefully by grinding off the lower part of the locating rib on the rear face of the mag casing. The two I have were well done & I wonder if this was officially sanctioned??