On sale date from the publication date found at the Catalog of Copyright Entries, Part 2, Periodicals, New Series, Volume 35, 1940, Number 2. Second class permit. Copyright number 448286.
In 1940, the Fantom strip was written by George Kapitan as well as Paul Gustavson and Frank Thomas. No extant evidence exists that is known as to who wrote this particular story.
Same applies to the artist of the story. Besides Gustavson, other known artists include Al Anders and Will Roland.