Most probably Correa art. He is not credited on Black Diamond by Jerry Bails' Who's Who, but this art is very similar to his story in # 27. Best spotted by the eyes, and his very accurate copying of work by John Prentice. The character Sioux Sam Dancer on page 6 has the long face and tilted hat with very narrow brim of Buckskin Benson in Hillman's Western Fighters by Prentice.
Middle column of a three-column page.
Inside back cover.