Levi has explained most of the intellectual property (IP) situation. POTO was a hot show at the time, and Stern/DE figured out a way to use the theme without licensing any of the new IP assets. Artist Paul Faris talked about this in his presentation at Pintastic New England. He was told to read the book but not go see the show, and create the art based on the original book.
Since then, many people have emerged who do re-themes, changing the music, etc. New possibilities have opened up.
.................David Marston