Hmm, tempting. I did write part of some fan sequels a few years ago. They were based purely on the L. Frank Baum ones. I have enough vague memory of the ideas I could probably do it. I'd have to re-read the books to do it justice, but it could be interesting. I'm not sure if the Wogglebug has been represented in any media outside of the books. I'll see what I can do.
I noticed the trend in the books of Glenda getting rid of magic. The first story I had in mind would be about the last of the magic other than her own being removed and the repercussions. And would somehow have Uncle Henry, the Wogglebug, and Oscar Zoroaster involved with a university. And that's all I had figured out for that story. My focus had been more on one further off, set more or less modern times.
So, I shall attempt to make The Last Magic of Oz. Unless a better title comes to mind.
And I realized since it's November, I could write things out and use it for NaNoWrimo to kill 2 birds with 1 stone.