Stamps from the British Postal Museum and Archive (BPMA), including valuable duplicate Seahorse registration sheets, are to auction at Sotheby's London on July 11.
Registration or "imprimatur" sheets are among those most highly prized by philatelic enthusiasts.
Among the highlights of the sale will be one of only two 1923 Seahorse 10 shilling registration sheets ever produced. The BPMA is to retain the priceless original, while the duplicate is expected to bring £120,000 ($181,577) to Sotheby's.
These registration sheets have never previously been available to collectors, and we anticipate enormous interest.
The Seahorse duplicate sheets register original designs from the reign of King George V - himself a fanatical stamp collector.
Richard Ashton, a philately consultant to Sotheby's, described the sale as truly exceptional.
"Now in my 50th year as a professional philatelist, I have never seen such an important sale of this type. Many are the only examples of their kind to come on the market," he commented.
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