Tiverton Junction, Willand, in Devon. Well done in finding the missing part of the puzzle.
Almost spot-on. The dump was a little way north of the sewage farm site. I don't have an aerial photo but have theses two maps. The depot was very small an I almost missed it. It appears to have been on maps into the eighties.
What is so wierd is the fact that the Beeston site is near Tiverton in Cheshire.