This is Giant Western Comics 4, published by Mimosa (SA Magazine Co) in 1962.
It reprints both stories from DC Comics' All-Star Western 119 (1961):
Johnny Thunder: "Ghost-Town Gunfight"
Super-Chief: "The Sky People"
Also reprinted is this story from DC Comics' Tomahawk 21 (1954):
Tomahawk: "The Man with the Cane"
Also reprinted is this story from DC Comics' Western Comics 85 (1960):
Pow-Wow Smith: "Treasure Trail to Tumbleweed Gap"
48pages, glossy colour cover, black and white newsprint interior.
Here is the cover of issue 4 and DC Comics' original cover of All-Star Western 119 (1961):
Mimosa Western Comics Series