The previous two notes identified a counterfeit Charles I shilling, of type 1b2 mintmark Heart. The quality suggested it was cast from a genuine coin, and so the search began to identify dies of this scarce issue and mintmark. Ultimately the counterfeit was found to be a die duplicate of Brooker 434. The die study has been extended to look at 34 coins, with mintmark Heart, from 14 obverse and 16 reverse dies. The results are presented here.