Watch List notes:

British Tokens, Eighteenth Century Tokens, Norfolk, Norwich, Dunham & Yallop, halfpenny, 1793, City arms, sword and mace behind, rev. shop front, eagle within circle above (DH.29), extremely fine and toned, minor edge flaws on reverse, extremely rare
*ex Baldwin's vault
'Not more than three are certainly known', according to Sharp in 1834, but probably not quite so rare as that. The figure 3 in the date cancels a 2.
Estimate: 120-180 GBP