Seeking Help To Identify A German Reich Perfin

Hi!
As a long-time collector of worldwide perfins, I usually spend more time helping others identify their perforations. This time, however, I'm at a loss myself. Perhaps someone can help me with this perfin.

The letters "DE" are visible, along with another perforation above it made of larger holes. The place of use is unfortunately not fully legible, but "…SBURG 1" can be seen.

I'd bet the cancellation is "Duisburg", city with a population of around 500,000 today. There are a lot of cities ending in -sburg, e.g., Flensburg, Augsburg, Regensburg, etc., but I believe Duisburg is the largest.

The letters DE are the first two letters of "deutsch" = "German", so there are no doubt
several possibilities. Perhaps the experts will weigh in?

PostmasterGS has the 3-volume German perfin reference. (Perhaps others do, too, but no one has stuck his or her head up above the foxhole.) Maybe he will see this thread, but I don't think I've seen him here for a while? I know he's out there.

Every once in a while I think I should buy the set, but common sense prevails. 2100 pages of German perfins? Glorious? Sure. Too much? Probably.

PostmasterGS is very active on TSF.

"I'd bet the cancellation is "Duisburg" ... no, not in my PDF catalog.
I tried all "sburg" combinations so far.

"2100 pages of German perfins? Glorious? Sure. Too much? Probably."
In a common system - yes. That would be almost 40 albums with 60 pages. But I took transparent pages for photo negatives, cut each single description out, and have now 24 Leitz XXL binders. Quite some work (it took me half a year), but now I'm just about done. I'll post some pictures when it's completed.

Strange, betting the cancellation is from Duisburg, because it is the largest city ending in "sburg."
It might as well be a hamlet in what is no longer in Germany. Not all companies were located in the biggest cities.




I do not know what there is no doubt about, but chances DE stands for Deutsch or Deutsche are small. It is possible and maybe probable that "D" does, but it is not beyond doubt. If the cancel is for Flensburg, the "D" might even stand for "Dänische" or "Dansk."

I think we agree. I said "so there are no doubt several possibilities", probably more than several.

Thank you very much for your helpful tips and ideas. Unfortunately, every lead so far has turned out to be a dead end, but I won't give up—sooner or later, a letter with this perfin will turn up.

Have this 1926 German Rhineland stamp with the 'GL' perfin - the L having an uplifted base. can anyone help me with what the GL would stand for?

This is GL-1-01-09, Gustav Liebender, mechanical embroidery, Oelsnitz (Ölsnitz), in use 1926-1944

Thank you so much for your assistance!