Andrew, I have changed the title of the thread to hopefully attract some more views.
At the time I moved the thread out of Murano, there were a couple of comments suggesting it might not be Murano and, other than your own initial posts, no Board members had commented that it was, or was very likely, Murano. Therefore, as Sue has said, moving (temporarily) to the general Glass forum is a better way to get more thoughts on an item that, within the GMB, appears to be in doubt.
I believe that David's point about, "Too often, this tag is lazily dangled in front of art glass purely to achieve a sale ..." was not a suggestion that you were trying to gain profit, just a general point of "loose attrbitions" that are sadly seen so much in online auctions and stores and also in many well established "antiques & collectable fairs".
Your addtional comment about the "2 very experienced art glass dealers (1 an author on the subject)" is useful new information. Can you say who that author is, and if they are experienced in Murano glass or art glass in general?