It's quite good, but only if you're expecting kiddie nonsense. It made me laugh.
THINGS IT GETS RIGHT
1. Its villain has a magnificent name. He's a crook, so... "Otto Krook had more to be afraid of than lions. He was afraid of being found out. Afraid of going to prison for the things he had done. That is why he sent for the police to arrest Joe Summer, the circus strong man."
2. Later, the strip tries to top this with a rogue elephant called Satan.
3. Thunderbolt Jaxon stands in for the strongman, giving Hugh McNeill lots of opportunities to draw amusingly impossible superhero feats. He throws people up to the high trapeze. He swings an elephant around by its trunk, although let's pretend to ourselves that that wouldn't result in horrific trunk injuries. He does an unusual juggling act when Krook's thugs try to beat him up. "Gosh! Juggling with men!" ("Scream!" "Scream!")
4. "So Thunderbolt Jaxon gathers up Krook's trio of ill-treated lions and, carried by the power of the magic belt, flashes around the world to Africa."
Yeah, I know. I'm praising cartoonish, superficial nonsense. Well, so be it. Anyone expecting a 1949 kiddie superhero comic to be Alan Moore needs an expectation reset. The character's basically Superman with a slightly sillier physique, so give us amusing Superman exploits. That we get. Job done.
The artwork's unremarkable, but fine. (McNeill draws an exciting elephant.) The plot's perfectly acceptable for nine pages. I quite like the "small boy turns into Thor" conceit, with Jaxon starting and finishing the story as a small blond boy. This is jolly good fun, chaps.