Stu in fairness I am the opposite, I tend to use Withers as my reference, and have not really looked at North/Spink in any great detail for this series, and that has mainly been due to the fact that Withers break the classifications down in to greater detail . Withers do show the dates overlapping, but the series is broken down int smaller time periods. Type 28-29 : 1300-1310 Type 30 : 1310 -1314 Using date alone the type 28 could potentially be attributed either way, however type 30 has been attributed to Edward II. Although Withers do clearly state that they feel the farthings are not that easy to classify from a date perspective because of prolongued re-use of the remaining dies, and therefore additional combinations can be found which could potentially have been produced during either reign, but for the purposes of classification they have been attributed to a specific time period.