Mike, thanks for the input, interesting story about the court case too. I know Consolidated Glass in the US seem to have got away with copying Lalique's Perruches vase, though these are rarely seen outside the US. I also have a good quality ceramic copy of the Ceylan vase which I've never been able to positively identify.
I'm not sure about the Verlys attribution as yet though; I used to have a large collection of Verlys, both French & US production and never encountered this pattern before. The finishing isn't what I'd expect from Verlys either. I've had a look through McPeek & McPeek's Verlys of America (1972) and the Verlys sections in both Decelle & Cappa but couldn't find it, though I don't have a copy of Verlys of France or a full copy of the 1933 or 1937 French catalogues to check at present.
All the best