Gentlemen sorry to inform you but if that Bimingham private View mark is correct, and as it's stamped on the barrel there is no real reason to doubt it, then the rifle was not proofed in that condition until after 1950 when Birmingham first used the leters either side of the crossed lances. The private View came into use first in 1921 and it had a single letter at the top between the crossed lances.

If you can give a better close up photo of the view mark then we can tell when it was proofed.

Edit:-

This is the Birminham Private view mark:-

The confusion is that this particular mark does not apper on the list that the proof house supplied.