That is what I was looking to find out.....
Although the shape of the piece is reminiscent of some Kralik forms, Kralik is not really known for using gadgets to hold glass once removed from the pipe. The examples from Kralik similar in form to this have applied rims and prunts, and also have pontil marks. Generally Kralik production with an applied rim has a pontil scar, and almost all pieces I have identified as Welz production in this kind of technique (applied rim color) have no pontil mark. Based on that I would lean towards a Welz attribution for the piece.
There is always the possibility that Kralik played a little with gadgets in production, but even their later production of high end cased work has pontil scars, and I can not think of an example of their work I have seen that does not have a pontil mark, but normally would....
I had a small covered dish which I lost in my shelving unit collapse which was quite like this decor on a clear ground. I had attributed it to Welz. I do see some examples of their decors on clear grounds without an interior lining which is opaque, but it is in the minority of their production from what I can tell so far.
Hope this helps,
Craig