Geograph - photograph every grid square

This was a well known rally but closed permanently soon after due to insurance and organisational concerns. This was my only visit but I was hoping to go back as the lure of a working Ruston steam navvy is extremely strong. It has taken me many years to locate this picture. I was looking in the wrong part of the country until I found a reference to a machinery sale for Knowl Hill near Reading. I then looked at the aerial view and realised that it still shows the railway tracks either side of the depression where the navvy was displayed. QED! The view direction is my best guess. The navvy was being operated with a narrow gauge railway with De Winton vertical boiler locomotive Chaloner.
The Navvy went to Wantisden for demonstration at another rally but that too ceased to be before it could be shown. I do not know its current status or whereabouts.