It reprints the story Sky Devils Die Hard which originally appeared in the M.V. Features issue Action War Picture Library #13, 1966. The cover to the Page Publications is illustrated by Keith Chatto, and is based on the original cover to Action War Picture Library #13:
Such recreations of M.V. Features editions by Chatto are not uncommon in the Page Publications editions. It will be interesting to see if subsequent reprintings of this issue by Page pay homage to this image, or whether they appropriate an image from the interior art, say the splash page or some other key image.
For an example of this pattern, see Chatto's version of the cover to M.V. Features' Action War Picture Library #2 for Page Publications' War in the Desert #1, and the cover for the subsequent reprinting by Page for War Adventure Series #11. See also the cover to War at Sea #1, based on Action War Picture Library #24, reprinted with a new cover in Navy Battle Library #2 - the latter doesn't appear to have a signature, but to my eye, the waves are similar enough to other such illustrations to attribute it to Chatto.
In this instance, the cover art is sourced from interior art:
Update: Sky Devils Die Hard was indeed subsequently recycled by Page Publications - in Air Warfare Picture Library #2: