This issue has variants.
Distributed to newstands in January 1964. This issue includes 10 pages of paid advertisements.
Distribution date from Joseph Marek's Marvel Comics Group history website.
Letters credit from George Olshevsky's Marvel Comics Index.
El Toro next appears in West Coast Avengers (Marvel, 1985 series) #33 (June 1988).
Continues in next issue.
Average monthly paid circulation/print run October 1962–September 1963 (issues #39–51): 189,685/321,646. Paid circulation/print run for issue #51: 187,995/318,339. This shares the page with the promo.