This is Giant Woeste Weste 4, published by Mimosa (SA Magazine Co) in 1962. Mimosa produced reprints in English, and some Afrikaans language translations.
It reprints this story from DC Comics' Western Comics 51 (1955):
Rodeo Rick: "The Fool's-Gold Prospector"
48pages, glossy colour cover, black and white newsprint interior.
The Mimosa Cover image is taken from the splash page of this story:
Matt Savage Trail Boss: "The Trail of Vengeance" from DC Comics' Western Comics 79 (1959)
Cover of Issue 4 and DC Comics' original cover: