Just a little clue, but I believe that the correct lastname of Stefano's wife was Marantelli...
Both Marantelli and Pola are lastnames present mainly in the province of Sondrio, Lombardy region. (Marantelli especially in the town Bianzone)
Try this site:
http://italia.indettaglio.it/eng/cognomi/cognomi_lombardia.h...Laura