Dating is an estimate from www.ausreprints.com.
This is probably episode 53 of this series.
The artist's signature is dated '63. Other printings of this story include Ringo (K. G. Murray, 1967 series) #11, March 1970 [A Man Returns to Greenwood]; Cowboy (Ursus, 1972 series) #1, January 1971 [Un hombre regresa a Greenwood]; and The Fastest Gun Western (Federal, 1984 series) #nn, 1984? [The Day He Came Back to Greenwood]. It is unlikely that the Australian printing in Ringo #11 is the original version. This is a different translation to the later version titled "The Day He Came Back to Greenwood".
This version of the story has been retitled and is probably from The Rider (Ajax; Farrell, 1957 series) #?, although the lead character is referred to as the "Lone Rider" in the story.
This item is a K. G. Murray house advertisement, based on the back cover of 100-Page Super Spectacular DC-15. Part of the "A" symbol on Aquaman's belt has been left on the figure that has been converted to Superboy, even though other elements of the constume have been drawn in correctly.