This is All-Star Western 16, published by Mimosa (SA Magazine Co) in 1960.
It reprints the cover and both stories from from DC Comics' All-Star Western 116 (1960):
Johnny Thunder: "Mystery of the Masked Menace"
The Trigger Twins: "Gun-Shoot at Rocky City"
Also reprinted is this story from from DC Comics' All-Star Western 97 (1957):
Foley of the Fighting Fifth: "The Paymaster of the Fighting Fifth"
32pages, glossy cover and newsprint black-and white interior pages.
These titles were printed in a smaller size (187x132mm) compared to the original DC Comics title.
This is one of the seven first titles that Mimosa started reprinting in 1959 (Western Comics, Tales of
the Unexpected, Falling in Love, Mystery in Space, Romances, Batman and
Here is the cover of issue 16 and DC Comics' original cover:
Mimosa All Star Western Series