The variety Folm, is indicated as a unifere variety, Niagara black is bifere?
Natalegna is probably a synonym of Natalina, that means who the fig ripe in the Christmas period (Natale=Christmas).
Also the variety Vito is indicated as unifere, N.d. Caromb is bifere.
Regarding the Zingarello nero compared with Lampeira, i don't know, Lampera and San Pedro it's the same fig?
In Italy the variety called San Piero, is called also "Lungo del Portogallo" (portuguese long), and in the past "Lampas portoghese" (lampas from figo lampo?), the name does assume its portuguese origin.
I have a Lungo del Portogallo and it's different from Lampeira, and mine produces 2nd crop without caprification (at least i haven't never practiced).