Hi
Your photos are quite difficult to see the shape of the glass and the stem. If you could photograph them against a shadow or perhaps against a dark background now , the shape might show up.
Lobmeyr used iridescent glass for their wineglasses but I couldn't really see if there was any match to yours online because of the shape.
Is the stem quite intricate? and it would be good to see clear pictures of the merese on the stem.
They might be worth searching for though.
Where did you find/buy it i.e. which country?
m