The on-sale date is from the publication date recorded in the Catalog of Copyright Entries, Part 2, Periodicals, 1940, New Series, Vol. 35, No. 4.
Script and art credits by Michael D. Fraley per interviews with Sven Elven's widow and son-in-law and documents they provided. See article in Alter Ego #162 (January 2020).
Battefield is credited on pencils and ink in the Devil's Dagger story in Master Comcs #8, and that art is similar to this story. The faces of the villains are exact matches, long chin, small eyes and long noses. Also notice the face in sideview in the Battefield scan on Jerry Bails' Who's Who from Target comics with pencils by Battefield, and from the same period.
The art here is very similar to Binder's signed stories like Cloud Curtis and Black Owl, especially the inking.