As an RAF cadet officer in the mid-70s we were given two old AA shells by a local man, to be used, he said as trophies for competitions. One of our lads got his father, a good wood worker, to make mounts for them. Then they were taken to an engraver in Belfast where they were found to be live, and active. The altimeter fuse had been set. The local man said he had found them at the dis-used airfield near him and had kept them on each side of his fireplace since 1945. We never got to use them as trophies, the army kindly disposed of them for us.