Strange Tales #4, c. April 1981
The front cover to Strange Tales #4 originally appeared on the US Strange Tales #115.
Strange Tales #4 reprints the Human Torch and Doctor Strange stories from US Strange Tales #'s 115, 116 and 117. It even reprints the other two covers in black and white.
This means that this issue also carries The Origin of Dr. Strange. Which means this splash page is included:
Now that would have made for a cool cover on a digest-sized Page Publications comic! /Alas...