In the bonus footage, Mario Puzo says with all his heart, that Godfather 4 would be a sure hit.
The premise is that it would show the rise of the Corleone family in the 20's & 30's.
I totally agree.
Some of the best scenes in the book were about a young Vito consolidating power and rising to be the premier Don.
I really think this should be considered by Paramount.