Hi Dirk, I am still undecided as to the attribution of your piece. I have seen the label before though. One observation on the glass is that it appears to display a characteristic that I have not been able to attribute to any other manufacturer of the region yet. The characteristic is the use of double lines in the darker vertical stripes in the decor. If you look at the image of the purple dish I posted you can see the double lines in the darker area of the purple. They are a little more difficult to see there. It can also be seen quite clearly in other pieces of Welz in larger sizes and also different colors.
I have not located a decor by another Czech house that exhibits this particular trait. I have a couple of other Welz images that I will post that show it more clearly. I would be more inclined than not to say there is a strong possibility that the piece is later Welz, but to be honest with you, I am still doing a lot of work on Welz as a side project to the website. I have uncovered some interesting things though, that will be posted on the site when it is launched publicly.... Some of it will be, at the least, quite interesting....
The first image of the pink vase is actually a vase in the Passau Welz case..... The other two pictures are Welz vases also, and the decor of the orange one bears a strikingly strong resemblance to your piece.
The problem with using the label as a pointer for attribution is that it is beginning to appear that the label itself may be a generic shape of label offered by a printer(s) of the day, and as a result is turning up in several different forms...
While I am still being a little ambiguous

, I hope this helps....
Craig