I know who your grandparents and their ancestors were. In my tree on ancestry I have Francesco Di Leo (b. 18 Sep 1887), his siblings Paolo and Carmela (who married a distant cousin of mine, Girolamo Carubia, and thus I have her children as well), his parents Domenica Lo Raso and Alfonzo Leo/Di Leo, and his father's siblings and parents.
I have much more on Maria Smeraglia's ancestors, including 4 of her great-grandparents. Her uncle Emmanuele Smeraglia married Giuseppa Comparetto, whose nephew married another Carubia cousin who lived with my grandmother. However, not much is known about her mother Giuseppa Sarullo's ancestors since her mother Maria Sarullo was unmarried and her father unknown. Maria Smeraglia's grandmother Giovanna Casola was from Cattolica, which is also in Agrigento province, but the rest of her family was from Ribera, as was her husband's.
I have 5 sons of Francesco and Maria in my tree, too (Alfonso, Joseph, Paul, Dominick, and John). Maybe one of them is your father. Alfonso was the only one born in Italy.
Your grandmother is not the same as the Maria Smeraglia that I was discussing with Frank.
I can give you access to my tree on Ancestry if you'd like. It has more than 8,000 people from Ribera (and their descendants) in it, and attached to the profiles of many of these people are images of their birth, marriage, or death records. Just send me a PM with your Ancestry username.