When The Earth Was Young! - Okay. Plenty to nitpick, for instance, usually Eskimos in the arctic are in Alaska or Canada, so why would the Russians think they could enter someone else's country and claim the bones?
The Opal of Ali Khar! - Eh, okay, although as a rockhound calling it an opal, while not necessarily incorrect, there are jelly opals which are translucent, but generally opals tend to be opaque. A ruby or sapphire would have been a better choice. Also opals are fragile, a hammer would have reduced it to dust.
Most comic book publishers didn't have very good research done by their writers and artists. But ACG was lower than average, according to what I've seen. I really doubt that Russian "archaeologists" would have entered Alaska or Canada illegally during The Cold War, just to try to grab some dinosaur bones. What would archaeologists want with dinosaur bones, anyway??? Paleontologists are the scientists who study ancient animal life. How could an adult who writes stories not know that? The supposed T-Rex skeleton looked nothing like it should. The skull was the wrong shape. The neck was perfectly straight and way-y-y-y too long. I would have guessed that most people during the 1950s would have known this would have looked wrong. It was easy to just look at National Geographic Magazine at any library to find photos of T-Rex skeletons in the main lobbies of several musea around The World. When I don't know how to draw something accurately, I get a photo of it to use as a guide to the basic shape. I can't believe a comic book artist who needed to compete with others for jobs would not do proper research, to make sure his work would be the best it could be, so he or she could keep up a good portfolio and reputation, and issues containing his/her stories would sell better on average, than if he /she had been lax and sloppy.
Same deal with the opal vs. gemstones that are known to be translucent, and more valuable, and have a reputation for being connected to magic and curses in ancient lore. A special diamond, ruby, star sapphire, or emerald would have been a better choice.
Also, What's the point of choosing an unimpressive recent, 300 years of entrapment for the Jinn, when the author doesn't give any details of the owner(Maharajah, Pasha, or whatever type of ruler, or band of robbers). A 3,000 year entrapment connected to a curse, desire for vengeance, from ancient Egypt, or Sumeria, or Akkad, would be more impressive. But, of course, being restricted to only a handful of pages allows no room to tell such a story, and also show some action. I would have hated to be stuck with such debilitating restrictions when I had such a good idea for a story with such a good setting and plot.