A set of six mid 18th century silver picture front and back teaspoons

A set of six mid 18th century silver picture front and back teaspoons, probably by T and W Chawner, London circa 1765, the front terminals with a mask of a smiling gentleman, the reverse of the bowl with traces of a crown, scratch initialled to reverse of terminal 'R*H', approx. weight 2.6oz. (6)