If I had control over a GF4, I would make mainly about the past... I would use flashbacks for the time between Vito's revenge in Sicily and GF1, a short period between GF1 and GF2. Quite a bit between GF2 and GF3, showing Michaels children becoming closer to thier mother and how Michael legitimizes his bussiness's and then one final scene with Vincent as Don, but fairly old. His son has just become a Senator, Vito's last wish...

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