This is Mystery in Space 7, published by Mimosa (SA Magazine Co) +/- 1959.
It reprints the cover and the following 2 stories from DC Comics' Mystery in Space 52 (1959):
"Mirror Menace of Mars"
"The Man who met Himself"
24 pages, full-colour, newsprint stock cover and interior pages.
Here is the cover of issue 7 and DC Comics' original cover:
Mimosa Mystery in Space Series