Yes, it might well have been modded for a lefty. The cheekpiece certainly looks to be an original example though. I think the rifle looks a peach. True, the front pad screw slots don't align with the centre puch marks, but I'm sure the rifle is right enough. The front band is of the fabricated type & I have another couple of rifles that bear such a pattern. I think this was yet another wartime simplification.
One other note is the rare Vickers Mk2/1 scope........clearly manufactured as such & not a conversion of an existing Mk2. I have one fairly close in the serial range (No43 if my memory serves me correctly).
Interestingly the serial has been applied twice to the forend; I think the original being the number running from front to back along the forend. It has been added again standard No4 style, presumably after the event.
A nice piece of kit............but I'd have to change the cheekpiece back!!
ATB