

Original cover by Joe Gallagher; DC 1943. Jacob Steingroot's website is here.
Super DC Giant S-14 (On Sale: July 7, 1970) has a cover by Joe Kubert and features "Top Guns of the West."
Showcase #72 (On Sale: November 28, 1967) features a nice Russ Heath cover of Johnny Thunder in an issue branded Top Gun.