I'd definitely agree that it is Murano. To my eye, though, the style is more post 1960, following the style of Radi and then Aldo Nason. Search for Radi "Yokohama" line and you'll see what I mean. I couldn't suggest a maker. Interesting piece. I imagine that it was a very nice silk shade. I'd go with what looks good to you., but I wouldn't want anything that distracted attention from the body of the lamp.
David