Here's an interesting observation. JO-JO Congo King first appeared in issue #7 of JO-JO Comics (July 1947). Thereafter he became the lead feature, and after only a few months, 3 or 4 Jo-Jo stories were appearing in each and every issue. With the November 1947 issue of All TOP Comics (#8), he became a regular fixture of that title, appearing in one story in each issue between #8 and #18. All TOP #18 (the final issue) was dated the same month (July 1949) as JO-JO Congo King #29, which was also the final issue of that title. Jo-Jo's entire career spanned only 2 years -- but during that brief period, Fox Features published an incredible 685 pages of Jo-Jo stories! That is an amazing total for such a short-lived character. During that same two-year period, Dell only published a dozen issues of TARZAN!
Apparently, the single un-numbered issue of JUNGLE JO was simply using up a few leftover unpublished JO-JO stories with the character's logo removed from them, but the issues that followed (JUNGLE JO #1-3) are completely different, newly created material (the art style is strikingly different, as well). This is similar to what Fox did with TEGRA Jungle Empress #1 (which leads off with a Rulah story to which some simple art corrections and minor alterations in lettering have been made, to change the character's name to Tegra), and ZEGRA Jungle Empress #2, which look to be new stories, rather than slightly-altered Rulah stories.
Link to the book:
Jungle Jo 00
