It's a nice tidy rifle from what I can see. The A suffix rifles are not uncommon, & although it meant that that they might be difficult when it came to repairs, it did not mean that they were unsafe to fire. I do not believe that it came out of ROFF looking like that. Firstly, it appears to have been black painted (quite probably suncorite) which was not in use in 1942. The original finish is more likely to have been oil blacked early in the war. On top of this the charger bridge insert has been welded over. This occurred very commonly with repairs & refurbishment, as the little insert commonly worked loose, & 'slipping a gob of weld' on it was a sure fix.
I'm also not sure why the rifle serial has been stamped into the butt in the same place that scope numbers were stamped on No 4 T's......I don't think there was ever a requirement for it in
UK
service, although no doubt someone will correct me on this if I have it wrong.
But it's a nice looking rifle regardless.