Researching illegitimate children

[iamanappi]

I was told that my grandfather was an orphan and was adopted by Vincenzo Colonese.
However, in researching my grandfather I discovered that Vincenzo Colonese left Italy to come to the United States when my grandfather was only 3 years old and that he was single at the time.
My grandfather left Italy at the age of 12 to come to the USA and he listed Vincenzo Colonese as his father.
My assumption is that my grandfather was illegitimate and that Mr. Colonese was his birth father.
I know his town of birth and his actual birth date.
Is it possible that a small town would list the unmarried parents of a child born out of wedlock?
And how much information would I have to give to the town in order to find such a birth certificate?

[Italysearcher]

Request his birth record from the town under the name shown on the ship manifest. If his father 'recognised' him it will be written there. Ask for a photocopy of the original and it should even state to whom he was given for breastfeeding.

[iamanappi]

Thank you. I'll give that a try.