Alright if they actually did it then I believe they should obviously do it like Part II. One section about the rise of the Corleone's, with Sonny and all that, then the second part of it in the dreaded 80s and the early 90s. Even to the present day. There was never any clue as to when Michael died, they could make it 2002 if they wanted to!

-Penguin

Only after the last tree has been cut down
Only after the last river has been poisioned
Only after the last fish has been caught

Then you will find that money cannot be eaten.