Art credits from Greg Theakston. The central figure with the sword was swiped from a Hal Foster Prince Valiant strip. The first Jack Kirby cover work. Letterer credit by Greg Theakston in "The Complete Jack Kirby Volume One 1917-1940", page 166.
The Red Raven next appears in a story in X-Men (1963 series) #44.
In the spot where the "next issue" blurb usually appears there is instead a blurb for the Human Torch vs Sub-Mariner battle in the upcoming Marvel Mystery Comics #9.
This story is written by Martin A. Bursten, who is NOT an alias for Joe Simon. See https://comicbookhistorians.com/martin-bursten-is-not-jack-kirby/
next appearance in Tough Kid Squad (Marvel, 1942 series) #1
The "next issue" blurb instead tells the reader to follow their favorite characters every month in Marvel Comics.
Mercury possibly next appears as Hurricane in Captain America Comics (Marvel, 1941 series) #1 (March 1941).
A small "next issue" blurb promotes the Human Torch vs. Sub-Mariner battle in Marvel Comics.
Letters credit identified by Greg Theakston and later Harry Mendryk on the Jack Kirby Museum web page http://kirbymuseum.org/blogs/simonandkirby/archives/2369, 31 October 2008 (retrieved 15 December 2014).
The space for the "next issue" exhorts the reader to buy Mystic Comics #4 instead.
Letters credit identified by Greg Theakston and later Harry Mendryk on the Jack Kirby Museum web page http://kirbymuseum.org/blogs/simonandkirby/archives/2369, 31 October 2008 (retrieved 15 December 2014).
next appears in Daring Mystery Comics (Marvel, 1940 series) #7
A panel-sized "next issue" blurb instead advertises "The Battle of the Comic Century! FIRE vs WATER" in Marvel Comics, with head shots of the Human Torch and the Sub-Mariner.
Art credits from atlastales.com. Also signed in the second to last panel.