L. Frank Baum wrote Rinkitink in Oz around 1905, sometime between The Marvelous Land of Oz and Ozma of Oz, but we know that as originally written it had nothing to do with Oz. But Baum couldn't get it published as it was, so around 1915 he wrote a new ending, with Dorothy appearing late in the story (and seemingly from nowhere) to solve everyone's problems; then the non-Oz protagonists of the novel get a tour of Oz and meet the characters from the previous Oz books. The result was published as Rinkitink in Oz in 1916.
Do we know whether Baum ever finished the original novel? If so, is the original ending still around somewhere? If it's lost, do we know anything about what happened in it?