Thanks Chaps, Already seen those, and I've also read the excellent 'Vertical Empire' by Nicholas Hill.
I'm aware of the Test Stands At Greymare Hills And Priorlancy Rigg. Apparently this is something which has only recently been rediscovered. English Heritage are trying to 'Interpret' this find.
I knew that a start had been made on building a test Silo at Woomera, but that was just a boiler plate for launch testing as all the services were to be above ground. I'm Wondering what they were going to do at Spadeadam? Was it to be a complete prototye of the operational versions or just for test firing?