Although no dates have been found in any of the Pocket Love Library indexed so far, we can use the cover price values to estimate when the issues were published.
Various issues of Pocket Love Library have been identified. Issues up to #14 have a 1/- cover price. Starting at #17, the issues have a 6p cover price. So it seems reasonable to assume that somewhere between #14-#17 was when Decimal Day (
https://en.wikipedia.org/wiki/Decimal_Day) occurred. This places the Pocket Love Library series around 1970-1971.