File:The Model Village, Eastbourne Redoubt - Geograph.org.uk - 1435952.jpg
The redoubt was constructed as part of the defensive strategy during the period of the Napoleonic wars in the early years of the 19th century and was a barracks and supply depot for the nearby Martello towers. It is a scheduled ancient monument.
Best estimate for the date of photograph is between 1966 and 1969.
Another view of the model village: https://www.geograph.org.uk/photo/1435962
A 2009 view of the inner area of the redoubt:
https://www.geograph.org.uk/photo/1396085(required by the license)