Here is a possible search stradegy: If he was born after 1867 he would have to serve in the military. If you go to the provincial archives for Agrigento you can review these records. It is my understanding they are arranged by year, so if you know when or about when he was born you can find him. And you know the name of his parents, so you will know you have the correct person. This record will identify the comune he was from.
This is covered in Tafford Cole's book on Italian genealogy in the chapter on military records. I do not have my book with me at the moment to check the details, so I am not sure if the year of birth is 1867, but it seems it was about there. Perhaps someone can check the dates for me.
You are welcome. I am going to visit Sicily for the first time this fall. I can't wait.
This is from Cole's book Italian Genealogy Records.
Chapter 9. Summary, beginning on page 145.
Conscription and Military records.
In 1865, one of the first acts of the newly formed Italian state was the imposition of the draft - conscription of all able males at age 18. As a result, conscription records document every male born brom about 1855 to the present who did not emigrate at a young age. The year the records are available vary from place to place, but in most of Italy they are present from around 1873, starting with men who were then 18 years old and thus born in 1855. The conscription records list all males by year of birth for each military district. Usually these records are indexed. They are available in the provicial archives. Military districts are usually within the geographical area of a province. The records are called "registro di leva".