Hello Diana,
I read your topic only now, since this is one of my first times here on ItalianGenealogy, where I've usually been surfing without being subscribed (till now!).
I'm very interested in your message, since I was born and still live in Benevento, and San Giorgio del Sannio, Calvi and San Nazzaro are all very near to me.
If you are still interested, I just can help by saying that
FTM is not wrong in suggesting you
San Nazzaro Calvi, as those two villages were previously gathered into a unique municipality. They have been separated only from 1958 on, so civil status records from 1809 till 1861 (which one may find at the State Archive of Benevento) are yet under the old name
San Nazzaro Calvi.
Apart from the military entitlements, it is not possible to have other genealogical information about our area on the Internet. In case you're still interested, I would be very happy to help you search around

I've just sent you also a Private Message on your account... hope to hear from you soon then!
Alessandro