ESC 3571, S.3980.
The key date in British 20th Century silver coinage. Extremely rare in high grades. If this coin were graded within the MS grades it would be a £10,000 coin.
Slabbed and graded by NGC as AU58.
A recent AU58 in the Spink 'Waterbird Collection' sale on 24/09/2019 realised £5,500 hammer.