That
Evans is very lovely!
I heartily agree with those who suspect the frame is older than many or most of the components. The Benelux rod changer is from the late 50's, and I don't believe the chainset is any older. The brakes are, I'm guessing, mid 50's. But I believe the frame is older.
I don't know how old. But here is what I know:
I have a Fothergill made with the same lugs, though a different fork crown. The bottom bracket shell on mine is an oil bath unit: the cups thread into a removable cylinder held in by two bolts in the bottom. Mine has Chater Lea rear dropouts. I don't know how old my Fothergill is, but it is obviously a lot older than 1950. The lugs etc are, I believe, Brampton; and were made in the late 30's. The frame may have been assembled later; the bicycle industry went into a bit of a hiatus during the war, and when they started building frames again the pre-war lugs are the only available stock. So I believe my frame was made either a little before WW2 or immediately after it. There's a faint possibility it was made during the war, but I think that unlikely.
I attach a photo that shows the lugs pretty well. I got it as a bare frame, so the components are not original.
At any rate you are very lucky to have found this Evans, especially with its original paint in such beautiful condition!