Thanks for all your help.
Thanks John. There are one or two with pinched rims and the controlled bubble looks similarly tight, but none match the shape of mine (mind you, the thumbnails are frustratingly small!) Then again, it is similar in style to the one on 20th C Glass, which is attributed to Bang/Kastrup. I tend to agree with you Craig as the colours are unusual and the bubbles are very well structured. I supposes it could still be one of the smaller artisans at Murano though.