I’ve just had breakfast with Peter Rosengard, a genial insurance salesman who transacts all his business from a corner table at Claridge’s.   A few years ago, he had the idea of commemorating 9/11 by exhibiting one of the twisted steel girders from the Twin Towers.   For a while, it was displayed in Battersea Park.   Then, it was destined for Potter’s Fields south of the river.   Currently, it is being stored in a farmyard in Cambridgeshire.   The plan is that it should find a permanent home in Olympic Park.