‘Mona Lisa’ of postage stamps is again world’s most expensive – Press Herald
'Mona Lisa' of postage stamps is again world's most expensivePress HeraldDavid Beech, a longtime curator at the British Library who retired last year, has compared it to buying the “Mona Lisa” of the world's most prized stamps. The last owner was John E. du Pont, an heir to the du Pont chemical fortune who was…