Thanks to the Archive I found the cause of a top end rattle which occured on a recent trip to France . The car kept running ok so I chose to ignore the noise until we got back. It sounded like itwas coming from the area of the carb, not the cam/valves, and on removing the carb found a steel sleeve had come loose, it has a lip to locate the carb accurately on the inlet manifold. Its glued in place now and the engine is quiter than ever! so no more ding ding ding! 