A previous note provided illustrations of the known official issues of the shillings from the York mint during the Civil War. This note will present details and discuss five known varieties of counterfeit shillings which display the EBOR mintmark. Some of these show quite competent engraving skills, sufficient to allow the die that was copied to be identified.
The contemporary counterfeits showing the EBOR mint signature show letter and design punch links with each other and also with other groups of contemporary counterfeits of provincial mint shillings (Oxford).
All specimens of one York die combination show significant flan curvature pointing to manufacture on a roller or cylinder press.
Through the Commonwealth and up to the recoinage of 1696/7, increasingly worn and clipped silver coins fell prey to the counterfeiters. The whole topic of the state of the circulating silver coinage in the seventeenth century requires a thorough review in order to place what seems to be a continuous undercurrent of counterfeiting in its proper context.
BNS Research Blog 
Great work Gary!