del Fiacco does have (did have?) a concentration in Collarmele, Province of L'Aquila, Abruzzi (near Celano). It also seems a branch moved to Paterno which is very close to Celano.

My mother's (Irma Paolone) maiden name is del Fiacco (b.1939) - lives in Stoney Creek (Hamilton) Ontario, Canada).
Her ...