I did some additional research the other day, looking at other production examples in quite similar forms and have come to the conclusion that the pair above that I showed are Welz production. The only other pieces I have seen in the same shape are both decors I have identified as Welz. I also have a record of an additional example, which is the same shape and size with a different rim treatment, but the body and neck are identical to the other Welz examples. That example is in a decor of Green & White Honeycomb which is distinctly (at least until now) a Welz decor. Lastly I came across in my photo archives and example with the same body style, but a slightly different neck transition that is also in a distinctly Welz decor.
As a result, I have concluded, since every example of this shape, or extremely similar examples of the shape are, in my opinion Welz decors, that the pair shown above with the sellers image use permission, and the pair posted on CW are Welz examples. I would also note that the decor appears both with and without the Maze surface texture.
The surface texture, which I refer to as Maze, is also a decor I have started combing through my archives to identify examples of. Thus far I have located what I would consider to be 3 similar, but definitely different examples, supporting what I suspect, and that is that the decor was done by several houses in slightly different forms.
I am not aware of any direct link to Steigerwald for the vase in the CW post, and the same Unknown Production example in DBG IV pg 224. I think the link is confused, and the poster is of the opinion that the decor in DBG V examples and the DBG IV example are the same. I would disagree with that observation for the reasons described below.
The examples shown in DBG V pg 16 & v55 are a similar decor but in my opinion not the same. Without showing the images in DBG V here I will at least try to explain the differences I note.
The DBG V examples appear, and it could be lighting, to be a slightly lighter ground with overall lighter color. I have seen the decor shown in the small pair, which I have now ID'd as Welz, in several forms and it is generally a richer looking glass than the DBG V examples identified as Schliersee. Additionally the colors splotches (primarily the burgundy ones) in the Schliersee decor are seen in both examples as smeared or run color. These burgundy splotches also transition slowly from burgundy to the ground, which appears to be a deep Candia. This appears in both the neck and body of the vessels as a result of the blowing and manipulation of the gather.
In looking at the examples on CW, and other examples of the decor I have images of and have seen, the body of the examples with the burgundy splotches in the decor have a different appearance. They look like torn pieces of color in irregular patterns with much more definitive edges appearing where they merge with the ground color. It is more difficult to see in the small images of the pair, but I believe the same characteristic can be seen in those examples also. I also believe that this decor was likely produced in some slightly varying ground colors.
The difference I have described above is also visible in the example in DBG IV pg 224 identified as Unknown Production. In that example the "torn flags" of color can be seen all the way to the edge of the rim. This is also mildly similar to a very unique decor produced interwar by Welz in a kind of Yellow/Chartreuse and Burgundy decor. (examples below)
The first two images below show similar "torn flags" (for lack of a better term) of burgundy in the decor. The third image below is of two examples quite similar in shape to the pair I posted and in distinctly Welz decors. I would also note that I have never seen these shapes in any decors other than those I believe to be Welz, and the shape is not very common at all.
So, the decor on the pair, and the decor in DBG IV pg 224, I believe are the same decor and by Welz. I do not believe them to be the same decor as seen in DBG V pg 16 & V55. I believe that to be a different decor, and would have no reason to disagree with Passau on a Schliersee attribution .
The Maze, or Brain decor is, I believe, a decor to be found in several variants from different houses.
I hope this is clear....
I will email you images of the two cited examples in DBG V for your comparison.