On sale date from the publication date reported to the U.S. Copyright Office found in the Catalog of Copyright Entries, Part 2, Periodicals, 1944, New Series, Volume 39, Number 1. Class B periodical. Copyright registration number B 624201.
Same on sale date given on the last panel in the Blackstone Meets the Wizard of Wanga in Super-Magician Comics (Street and Smith, 1941 series) v2#12.