Family structure after II (but before III)?

Who immediately takes over the Family business in New York, replacing Frankie?
Who takes over Rocco's position as #2 Capo?

If GFII ends in 1960, what is the family structure of the Family say in 1961? When does Michael truly divest himself of the Casinos?Does the Corleone Empire continue into the 1960s or is greatly diminished from the conflict with Roth?

These are questions that have been asked before, and haven't been answered, because there are no answers. Zasa has the "Olive Oil Business" in 1979, when GFII opens, but he looks too young to have taken it over immediately after Pentangeli turned rat.

Administration:
Boss-Michael Corleone
Underboss-Al Neri
Consigliere-Tom Hagen (until his death)
New York Faction leader-Nick Geraci (until 1961, if you don't disregard Winegardener's story and then Richard Nobilio)