I know this is an old thread, but I have only just joined your forum and so have been reading all the threads which may relate to Murano paperweights.
This is indeed a very good Murano weight - as Kevin says unusually neat in profile. On my website ( www.muranopaperweights.co.uk
) you will see a weight very similar to this on the 3 Fiori page. The canes are very similar, and the weight is the same neat profile. It is quite different to the other 3 Fiori weights. I always felt the canes were not 3 Fiori canes.
When I was last there in the glassworks, before they sadly stopped making paperweights, the chap I dealt with said that the only canes they bought in were the tiny ones used in the Bonsai (trees) series of weights. He said all the others they made themselves.
But having said that, 3 Fiori also made weights to sell to other glassworks to put their own labels on - Bucella Cristalli, ALT etc. So that can be very confusing too.