Years ago I have scanned parts 3 and 4 of a collection of Italian folk songs “Celebri Canti Popolari Itaiani” published around 1900 by Schmidl & Co. in Italy. Now recently I have got part 1 of this collection of Italian folk songs and have made it also available on my website MandoIsland.
You can find all 3 parts on the following page: Celebri Canti Pololari Italiani
I hope that I can get the missing part 2 some time and make it available too. I have collected videos of some of the songs in this first part of the collection.