See COVE Master Map entry: https://editions.covecollective.org/place/norfolk

In London Labour and the London Poor edition: 

Phase 1

Of the Street Sellers of Live Birds. (Volume 2): "The price of a piping bullfinch is about three guineas. These pipers are also reared and taught in Leicestershire and Norfolk, and sent to London, as are the singing bullfinches which do not 'pipe.'" 

Phase 2 

Of the Cheap Johns, or Street Hansellers. (Volume 1)