PZ Chapter Jewel

Hallmarked silver Past Z's Chapter Jewel.
Details on jewel as follows:
Suspension bar - 31st
M.E.Z. 1962-63
Enamelled Chapter Banner with crossed Three Principal's Sceptre's behind
Crown has three small stones, 2 red and 1 green unsure whether they are glass or semi-precious
Hallmarked on reverse with
TK89 - Anchor - Lion - Italic "N" which I believe represents the Maker; Birmingham;Sterling .925; 1962