Hi Michael,
the exact source for these very nice paperweights was researched by HR Gerd Mattes/Vienna a couple of years ago;
Gerd Mattes found out that this distinctive style was made by glassworks in Alt-Nagelberg and Neu-Nagelberg, directly at the Czech border - district of Gmünd/Waldviertel. Alt-Nagelberg is the bigger place, located in Austria, and an old glass making area. The name of the firm that exists still is Apfelthaler, the older examples of paperweights date back to the 1920ies and 1930ies presumably.
Gerd Mattes also collected an iron plate form for placing the flowers and twigs, and published an article about those finds in the PCC Newsletter some time ago, so this is definitely an "Austrian" and "Bohemian" paperweight, which is not always a contradiction: in strict sense, paperweights from Venezia from the 1840ies are "Austrians" as well, as Venezia was part of the Austro-Hungarian Monarchy that time, and reigned by the Kingdom of Italy later,
Kind regards from Lermoos, Tyrol, Austria, Erhard