Another two labels for consideration, although they do throw up a slight anomoly.
These are what I call 'Clam Dishes' due to the shape and are unusual as they have two ground and polished bases for placing upright or on their side.
Click any photo to enlargeThis first photo shows the three I have:

The next shows a rather worn, but virtually intact label and is on the blue/amber one to the right. This shows L. Nason as the maker:

This is on the small green/amber one. The initials are either 'DSV' or 'SDV'. Any help on this would be appreciated.

I suppose these demonstrate how makers would often copy each others designs, particularly if they proved popular. Unfortunately the red/amber one is not labelled.
I also have several 'V. Nason & C' labels that I will have to post — unfortunately I believe they closed down recently. This is the firm of Vincenzo Nason, who I believe was originally part of the Nason & Moretti group (comprising many members from each family) and probably related to L. Nason. There are other Nason makers; Ermanno being famous for his modernistic glass sculptures in the 1960s.