Watch List notes:

Victoria, proof halfcrown, 1881, young head left, rev. crowned shield, reeded edge (S.3889; ESC.2759), certified and graded by NGC as Proof 65, even light golden grey toning, very rare especially so fine, a proof of record
The only one graded as Proof-65 by NGC, none higher.

Estimate: 7500 - 8000 GBP