There were three provincial mints that issued pennies of Class 2bi; Lincoln, Northampton and Winchester. It appears that the class was short-lived, and that the issue of dies was limited. We have taken each mint in turn and examined the dies known to exist, identifying these along with the corresponding reverse dies used with them.
A recent article (Link) presented the class 2bi coins of Lincoln, and this article now moves on to Northampton, where there appear to be three obverse dies for Class 2bi. Included here are copious illustrations and some suggested means of die identification.
BNS Research Blog 