An E Mail from Ed Wainer
The tower as I remember it was isolated in the woods; no other structures around and nowhere near the road. It was built entirely of steel in concrete footings - no brickwork that I can recall. The framework was a lattice work of girders similar to electricity pylons and the platform at the top was an open box of flat galvanized iron sheet in a metal frame. Access was by ladder through a hole in the floor. If I were to guess where it would be on the map, I would put it slightly lower than the 'Chu' of Churchfield. We used to walk to it from the Southernmost tip of the wood, just past the junction of the two footpaths coming down from Wansunt Road.
Below courtesy of http://www.old-maps.co.uk/maps.html