Now this is interesting, hoover. As you can see I found this scan back in 2012. Since then I acquired a facsimile copy for myself. As you can see from our scan there is no ifc or ibc, and the first story page is numbered "3". Whereas, my facsimile, copied from an original, shows "1" on the title page of the story. The scan on CB+ is obviously an amalgam of the original cover and the interior of a later reprint from one of the other pocket library series. I'm struggling to remember which, though. Hence the change of title from "The Men From The Stars", which is the original title, and the title of our one, "Invaders From Space", and the different page numbering.
At first I thought our interior was from Buster Adventure Library bit it doesn't seem to be.