I mean look how hard GF Returns was to get through. Windegardner is probably a good writer, and even he couldn't make it interesting. I'm sure it could have been better, but is there any more stories to tell in the GF universe? Or are any new stories all too much of a stretch to make them a part of the previous book and movies?

A while ago, someone on this MB helped me along with a rough version for a part IV script about Vincent trying to become owner of a baseball team and meeting opposition from the owners and the league. Michael had a small part and there were flahbacks showing Sonny when he was younger. I thought it was a pretty good start, but then we hit a brick wall and couldn't really come up with anything riveting.

IMO, it would take a genius to make another GF movie and make it half as good as part III. And no it couldn't be based on GFR.