First: the document described last week (Clelia Zianna and her husband Francesco Pontecorvo bought 4 acres of arable land for 400 liras from Antonio Castorino, who was a musician):




Second: on Dec 3rd 1893, 325 people created a Company (Societa' Anonima Cooperativa di Consumo), whose target was to buy food at bulk prices. Each partner put 15 liras in the Company.
Within the names, there are:
68* Pontecorvo Francesco di Salvatore
69- Pontecorvo Giuseppe di Agostino
70- Pontecorvo Leonardo fu Raffaele
71- Pontecorvo Pio fu Gabriele
94* Zianna Francesco di Raffaele
112- Pontecorvo Alessandro fu GiovanBattista
114- Pontecorvo Francesco fu Giacinto
115- Pontecorvo Agostino fu Stefano
116- Pontecorvo Raffaele fu Antonio
135- Pontecorvo Tranquillo fu Antonio
As you can see, two names are already known (marked with an asterisk), but several more Pontecorvos lived in Valmontone at that time. Hope I can link them in some way in the future. In other documents I've found other names too. However, this document is interesting because it lists many (if not all) the families of the town.
Third: I went to the Valmontone's cemetery and found the grave of Clelia Zianna and Francesco Pontecorvo:

Hope this can be interesting for you.