A German speaker would be highly unlikely to put the street (e.g., Weyerburgstrasse) rather than the town. A lot of those German makers were small-town craftsmen, as opposed to the concentrated numbers in London, Birmingham, and such. Moreover, a German-speaker was abbreviating it, it would almost certainly read "Weyerburgstr.", particularly since it appears the maker did it in gold.
A skim of google's entries and German Wikipedia tells me the Austrian Weyerburg is a pretty small town, current population 144, in the Hollabrunn area of Lower Austria (Niederoesterreich) north of the Danube. There is, however, a castle which has been inhabited since the Middle Ages, indicating there was some money there. The pictures of the area indicate an agricultural rural area, probably not much changed from 150 or so years ago. From the minimalist maps I can get right now, it seems not too far from Vienna, too. I'll have to look at more detailed maps later - my train is pulling in.
And "Keidusch" sounds way more Austrian than Pfalzisch to me.
So, my opinion is "Austrian".
