A 1938 Morris Minor M8 Post Office Van and 1933 BSA GPO motorcycle are displayed the Guildhall Art Gallery on April 30, 2010 in London, England. The van makes up part of a collection of memorabilia commemorating the centenary of King George V and the General Post Office and opens to the public between May 7 and July 25, 2010 at the Guildhall Art gallery in London. (Getty Images)
A Guildhall employee stands next to a 1938 Morris Minor M8 Post Office Van at the Guildhall Art Gallery on April 29, 2010 in London, England. The van makes up part of a collection of memorabilia commemorating the centenary of King George V and the General Post Office and opens to the public between May 7 and July 25, 2010 at the Guildhall Art gallery in London. (Getty Images)
A rare blue Type B airmail pillar box is displayed at the Guildhall Art Gallery on April 30, 2010 in London, England. The pillar box makes up part of a collection of memorabilia commemorating the centenary of King George V and the General Post Office and opens to the public between May 7 and July 25, 2010 at the Guildhall Art gallery in London. (Getty Images)
A conservator puts the finishing touches to a display piece at the Guildhall Art Gallery on April 30, 2010 in London, England. The piece makes up part of a collection of memorabilia commemorating the centenary of King George V and the General Post Office and opens to the public between May 7 and July 25, 2010 at the Guildhall Art gallery in London.\n (Getty Images)
A 1938 Morris Minor M8 Post Office Van and a 1933 BSA GPO motorcycle at the Guildhall Art Gallery on April 30, 2010 in London, England. The van makes up part of a collection of memorabilia commemorating the centenary of King George V and the General Post Office and opens to the public between May 7 and July 25, 2010 at the Guildhall Art gallery in London. (Getty Images)
A Guildhall employee stands next to a Post Office Mauritius stamp with an estimated value of 2.8 million GBP at the Guildhall Art Gallery on April 30, 2010 in London, England. The stamp makes up part of a collection of memorabilia commemorating the centenary of King George V and the General Post Office and opens to the public between May 7 and July 25, 2010 at the Guildhall Art gallery in London. (Getty Images)