A rare Henry VII silver Wrythen Knop spoon

A rare Henry VII silver Wrythen Knop spoon,
maker's mark of a key, London 1488,
fig-shaped bowl, tapering faceted stem with a fluted Wrythen Knop finial with traces of gilding, the reverse of the bowl with an old collection label, length 15.9cm, approx. weight 1oz.

A Private Collection.
The Staniforth Collection.
Illustrated and written up in How, G., and How, J., English and Scottish Silver Spoons, 1953, Volume One, Chapter I, Section IV, Plate 5, pages 86/87.
How writes about this spoon. 'At one time it was in the famous Staniforth Collection, being then the earliest known dated spoon'.

For the maker's mark see Jackson's, Ian Pickford Edition, Antique Collectors Club, 1989, page 87.