Geneva - The largest-ever lot of British and Commonwealth stamps to be sold at one time will go under the hammer in Geneva in May, auctioneers said yesterday. Mr David Feldman SA, which has mounted major sales of elite collections as well as some of the world's rarest stamps in Zurich over the past few years, said the lot belonged to the London stamp dealer, Barney Kleinberg, who died last year after nearly half a century in business, leaving a vast stock of middle 20th century stamps, according to the Irish-born Mr Feldman.