On sale date from the publication date and the volume number found at the Catalog of Copyright Entries, Part 2, Periodicals, New Series, Volume 35, 1940, Number 2. Second class permit. Copyright number 453593. Volume number not listed in the indicia.
While the story is signed "Hank Christy", a known pseudonym for Fletcher Hanks, this does not appear to be by his hand
Jim Vadeboncoeur, Jr. wonders if this could be the work of Dan Gormley.