Some info verified using a DCM scan (http://digitalcomicmuseum.com/)
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. 3.
Art is identical to Volp's many signed and unsigned Loop Logan stories in Blue Ribbon Comics, from #4. He can be spotted by his very realistic horses in #13, bony faces with marked cheek lines and mouth inked in two short lines. Also the small lines on each side of nose or smiling cheeks. Compare as well his signed London stories in Daredevil Comics #9 and 10 (Lev Gleason)
The spells of Zabini can be read by skipping the ABs.