Difficult to say when this series first started. What is believed to be a 1962 example came up for auction on eBay UK in May 2012.
Jul 2018: philcomics as usual did a great job in offering an example of the #1 issue, the only one I have ever seen! And so confirmed for me that this series started in 1962 as suspected.
Note: some PR issues may have no value. Selected issues in FN, VF or VF/NM may not exist in some titles.