In 1982 during the Falklands War I was at RAF St Mawgan and we had a call about the WL795 Shackleton AEW2 which had arrived on the station in Nov 81 before I arrived. Apparently it had not been Cat 5'd (my predessor should have asked for that) and so the powers thought it was serviceable. They wanted to fly it down to Stanley, take the nose off and use it on top of one of the hills as a ready made radar station!
Happily that never happened, but I put in a Request for Categorization pretty quick!