No. Don't figure in the numbers Turnbull gave you (they become way too confusing when you try to reconcile what the movie figures against what is in the novel).
Exactly. That's why I said, "Go figure..."
A possible reason for the discrepancies between Vito's birthdate of 1887 in GF, and 1891 in II, is that GF didn't show Vito's early years, nor was there any plan for GFII when GF was released. So, according to his tombstone in GF, Vito was 68 when he died in 1955--consistent with Brando's appearance in the heart attack scene.
II opens with that dramatic and stage-setting tale of Don Ciccio's massacre of young Vito's family and his escape. Drama, I believe, was greatly enhanced by showing a nine-year-old escaping the evil Don's clutches, than if he'd been a 13-year-old making his escape.
As SC said, it's pointless to try to reconcile dates in the novel with those in the films. The novel says Vito was 12 when his mother sent him to America to escape Ciccio's clutches. The time frame referred to is "...at the turn of the century...", which could encompass a wide range of years--say, from 1890 to 1910, or if you prefer, 1895-1905. Puzo left himself plenty of wiggle-room. What's more, a 12-year-old Vito is more credible as going to work in the Abbandando grocery than a 9-year-old Vito.
