Obv: Shield of arms of Norwich, upon a sword and mace in saltire, between palm branches, SUCCESS TO THE CITY OF NORWICH around. Rev: A shop front in a circle, NORWICH HALFPENNY around, 1792 below. Edge: PAYABLE AT THE SHOP OF DUNHAM & YALLOP GOLD-SMITHS.
Issued to Dunham & Yallop. Robert Dunham was a silversmith in Norwich. His business would grow to include the sale of Tea and Coffee, thus explaining the TEAS above the doorframe. I’m guessing that his teas had a ‘metallic’ taste to them!