Leonardo da vinci's father was a notary as was the rest of his family except fot a few exceptions. his fathers name was ser piero and was the son of antonio ( i do not know the fathers full name). the da vincis all lived a life on the farm with little travel except for clients.
in my opinion, i think he is because Leonardo has helped ezio for many time and ezio knew Leonardo when he was very young. also, ezio told Leonardo classified secrets like the prophet and the pieces of eden his uncle told him.
it is Leonardo da Vinci, though that is not actually his name. In renaissance Italy, peoples last names were the name of the town or city they lived in. So if Leonardo had lived in Florence, his name would be: Leonardo Da Florencie. It is in fact the middle name you should look for.