Gregorio Mannino Death Certificate

So the last post was a bombshell - our last name was originally Mandina. I know some of you may have your doubts and I realized I have not shared the death certificate that will bring all of my findings together, AND, this is the first document that I see that contains the name MANNINO. Could it be that his death certificate was the document that changed our name from Mannina to Mannino??

Here are the images:

Here we have the names of Gregorio's parents. Antonino and mother's name Angela Loria.This is without doubt the right man because we know the address was 37 Starr Street in Brooklyn.  We also have the signature of his wife who was going by Jennie Mannino. He was buried on January 3, 1946. His principal cause of death was lobar pneumonia.