The next very narrow stretch of the A149 runs through Cley-next-the-Sea, which, like all good villages, has a phone box (and in this case a surprisingly detailed Wikipedia page).
(Coordinates 52°95’28.9″N, 1°04’29.3″E.)
I had to double-take a bit on Street View as the surroundings have changed so much (the Google cars haven’t been back to visit since 2009). This box is a bit faded, but still has a phone inside (and also a traffic cone for some reason).
More from this pretty part of the world next week.