A Crisp Percussion Turn Over Pistol by Dyball of Norwich. With blued turn-off barrels stamped with Birmingham proofs, foliate engraved beech block also stamped with Birmingham proofs either side, profusely engraved box-lock action, signed ‘DYBALL’ on a foliate scroll to the left and ‘NORWICH’ on a scroll to the right, fitted with a sliding safety catch, dolphin hammer, figured walnut grip with vacant oval escutcheon. 

Notes: 

The only reference I could find to Dyball is:

Dyball, Edward [about 1860]

Custom gunmaker in London. 

A. Merwyn Carey (1954) English, Irish and Scottish Firearms Makers, Acro Publishing Company, New York. 

Dimensions:

Bore: 80 Bore

Barrel Length: 2 Inches (5.08 cm)

Overall Length: 6 Inches (15.24 cm)