Watch List notes:

GREAT BRITAIN. Mint Error -- Struck over 1963-Dated Hong Kong 10 Cents -- 20 Pence, 1983. Elizabeth II. PCGS MS-63.
KM-931 (over KM-28.1). A tremendous error issue that was created when a 1963-dated Hong Kong 10 Cents was mistakenly put into the planchet feeder for the 1983 British 20 Pence issues.

Marvelous in its own right, this coin is elevated even further by the addition of correspondence between G.P. Dyer, who at the time was a Librarian and Curator at the Royal Mint, and a Mr. Farrar. The letter reads:

Dear Mr Farrar

I hasten to return the 20p piece of 1983 which you enclosed with your letter of 23 January.

The coin is of incorrect weight and composition, and examination has left no doubt that it has been struck in error over a Hong Kong ten-cent piece of 1963. Quantities of old Hong Kong coin have been returned to the Royal Mint in recent years and it is clear that one of these coins became mixed in with the 20p blanks and was then unfortunately struck by the 20p dies.

A coin dealer will be able to tell you whether such a coin is of any special value and, as promised, I enclose a slip giving the names and addresses of three of the largest firms in London.

Yours sincerely,

G P Dyer

Librarian & Curator

Estimate: $300 - $600