At FamilySearch there are several books, published by the City of Palermo, that index births, marriages, and deaths from 1820 on. These records, for births, give the name, date of births, parent’s names, office of registration, and specific citation for the birth record.
The volume that includes 1843 gives no Stefano Ruggeri, but does give four Stefano Ruggero’s. One of these was born 6 Aug 1843, son of Giuseppe Ruggero and Benedetto Romeo. The birth date is not a match, but is quite close.
For many of the Palermo resources you must be at a FHC, but for this link, you can use it from home.
Edit: this source is for the city of Palermo, not the province.