Hi
I believe that Italian Wills are usually lodged with notaries locally, so it is necessary to know where a person was living when they made the will / died, and then to approach individual notaries - small towns may only have one or two notaries, but there will of course be many in large towns and cities.
In this sense, Italian wills are not public documents in the way that English & Welsh proved wills are public and searchable at the Probate Registry in London or obtainable by post from the York Registry.
Sorry!