Watch List notes:

Great Britain. Uniface Silver Pattern 20 Pence or Double Florin. Elizabeth II. Struck at the Royal Mint in 1963 to the same dimensions (36mm diameter) as the Victorian Four Shilling coin. Obverse portrait of Queen Elizabeth II (without legend) by Machin. Reverse is intentionally blank. This is an extremely rare coin (probably only 2-3 pieces known) which formed a part of the Mint's numismatic experiments, before the dawn of decimalisation. Eventually a small multi-sided and quite different 20 pence coin was introduced in 1982, but some 19 years earlier the Royal Mint had obviously contemplated the provision of a 36mm diameter decimal 20 pence which would take the place of the (larger) 25 pence Crown coin. NGC graded MS-62. WINGS. Estimate Value $1,500 - 1,700