Copyright years inside are one year less than the cover date. So the cover date is the year that defines the annual. This is true of the vast majority of British annuals!
As well as this World Distributors series, Purnell also issued annuals from 1962 to 1969. Confusing have two different annuals with the same year inside. But there is a way to tell them apart.....
World Distributor covers are painted artwork, Purnell ones are photo covers taken from the TV series.
Note: some PR issues may have no value. Selected issues in FN, VF or VF/NM may not exist in some titles.