you can contact him on his website, his email is there, i already did contact him

and as for sonny's age i was going by the timeline and my book

THE CORLEONE TIMELINE Last updated - 27 Nov 04

*1911 - Las Vegas officially becomes a city
1914 - Vito & Carmella get married
1916 - Santino (Sonny) & Tom Hagen born
1917 - Vito's Little Italy sequence begins (De Niro)
*1917 - Sicilian (Mafia) Don Morello murdered by Neapolitan (Camorra) Don Morano
*1918-1922 - Merger of Mafia and Camorra. Giuseppe Masseria is boss.
*1919 - Prohibition begins
1919 - Vito (27) kills Fanucci; Fredo born, gets pneumonia