thanks. Glass in general acquires importance, and value, if the piece can be shown to have verifiable provenance/attribution, and that's something we aren't going to have with your pitcher. In the C19 and early C20 that part of the world was full of small independent glass houses, and unless the glass is signed or recognizable from it pattern, we will never know the maker.
I don't think there's any doubt its origin is eastern/middle Europe, although specifically which part we don't know, but Czechoslvakia/Austria are possibilities - parts of which were previously called Bohemia. Countries and borders in the aftermath of wars change, and that area is/was complex.
Whilst the decoration shows some nod to linear patterning in common with Continental design from the early C20, there is always the possibility that it was made subsequently and copying an earlier design, but at least you have answered the question as to why the condition remains v.g.
Glass designs have been copied as much as, or more, than other decorative materials, and never easy to be sure when trying to date. Perhaps it should be law that people keep their receipts

I doubt that you will fare any better elsewhere, but possibly there's always someone ready to put their neck on the block and commit to an actual date, but for my money first third of C20 or even first half of C20 is about as good as I can suggest.
It's a great piece and full of nostalgia for you - you're lucky to have this memento from your g. grandmother - don't use it.
You might care to post pix of some of your other pieces.
