It looks to be genuine but it's hard to imagine it being unissued. The electric pencil markings are suspect. Not that electric pencil markings are not to be found on issue British rifles, because I had one with such markings. It was a late manufacture No. 4. I cannot confirm what year it was made but late 1950s most likely. I no longer own it or any other rifle.
Your rifle, however, is clearly marked 1947. Could it have been factory refinished, do you suppose? The No. 4 I just mentioned had largely the same appearance, which included a thick varnish finish and not at all smooth or worn. The No. 5 that I had, bought around 1968 through the mail, just in time, had a nice, smooth finish that was considerably darker than both of the rifles pictured here. There was virtually no varnish and the surface finish was flat, rather like it had been oiled.
Shoot low, sheriff. They're riding Shetlands!
Underneath the starry flag, civilize 'em with a Krag,
and return us to our own beloved homes!
Buy War Bonds.