Hi,
This is a Murano weight, possibly from Fratelli Toso. Maybe mid 20th century?
I do not know what the "av" means, but in any case, the letters cannot be seen in your image.
Although your photos are ok for general ID they would be much better set to 600 or 700 pixels longest side. The board permits 125Kb per photo and if your images are set to that size and "saved for the web" they should easily fit under the KB limit. If you have trouble getting larger images down to the board limit just post a reply about it and we can point you in various directions for assistance.