The on-sale date is from the publication date recorded in the Catalog of Copyright Entries, Part 2, Periodicals, 1941, New Series, Vol. 36, No. 2.
Writer revision from ? to Toni Blum by Craig Delich 2013-12-30. The Who's Who indicates that Toni Blum wrote this feature in 1941-42.
Artist verification for Williams by the Who's Who.
It's a good bet that Blum did the art on this story as the only other artist known to have done it was Lou Fine in 1941 and his style is easily recognizable. Added by Craig Delich 2013-10-10.