LSA stuff is usually very good quality and its labelled stuff is quite desirable on fleabay. Your vase is pretty good quality; note the ground, polished and neatly chamfered rim. I wouldn't put its quality at less than than the Tapio Wirkkala version, just its desirability if it is an imitation. Anne's M&S one was made in China.
LSA is a design and import company; some of its stuff is Krosno and made in Poland, as is some of M&S's stuff. I have a labelled Krosno water/lemonade set bought from M&S in the 1970s. Krosno glass, when you can identify it, is good quality.
I was going to say that looking at the labelled TW Anne linked to, yours is not because the clear bit wasn't deep enough although the colour was good.. I changed my mind when I looked at Robbo's signed one. So maybe TW IMHO.