Some info verified using a DCM scan (http://digitalcomicmuseum.com/).
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 448697.
Originally credited Mort Meskin. Compared with his signed story in #6, this is not him, but George Storm. Compare also with Storm's story in Hangman #19, with long and lively inklines. He is credited on this feature by Jerry Bails' Who's Who.
Only the name Quincy as artist is found in Jerry Bails' Who's Who, no P. Quincy.