Your right about it being a minefield. There is a company making copies of Archimede Seguso's larger pieces that are well above Chinese but not as good as originals and a couple of guys asking big money for an average to poor copy.
The only thing you can do is exactly as you are, be ultra cautious, if it looks to be very well made, as yours appears to be, you have to be happy with that, assuming you did not pay a lot for it. You can drive yourself crazy trying to get a clear id on some of this glass.