Well done on the pics Kath
These were made as decorative items in many shapes, sizes and colors and in fairly large quantities in the 1960's.
To find the exact maker of yours would be a miracle. There were many competing companies in that area often doing similar types of stuff. Glass from this region is not much researched as generally made for the mass market.
If you like this type of (cased) glass look for the better quality items with a very white very opaque inner layer, good weight and good finishing. It's hard to tell the better ones from the others in pics but see items from these companies : Moretti, Holmegaard, Alsterfors
Here's a selection of mainly Italian, mainly better quality items (the green one is not so good). Exact makers for these also mainly unknown except for the ones with labels.
see also herehttp://www.vmglasshouse.com/CasedBlueGreen.htm
and the other "Cased Gass" pages on the same site.