Notes:
Joe Simon began editing for Timely on a freelance basis with Red Raven Comics #1, which came out the same month as this issue. It is not clear if he immediately started editing Marvel Mystery Comics as well or not, although he was definitely the editor by issue #12 as discussed in that index.
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. 3.