Hi Rande, welcome to the forum I live about a mile from the site and part of the building is a museum now, Tarkey, I am sure, will fill you in with some details
The guys at the Site have a website but it doesn't work at this moment. Their Chairman is Coiln Durrant and ex Parham. I haven't been yet but I'im told it is a nice set up. Colin is absolutely sure and I have discussed it with him that there is no underground bunker there but others don't agree, The late Michael Elmer who was on the Suffolk County Council Planning Committee said he visited a huge underground complex at the planning stage. He said it covered the area of the big field up top.