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. Class B periodical. Copyright number B 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.