Thanks everyone for your information, opinion and last, but not least compliments - really appreciated.
As for the photographs I could make a short explanation in another forum of this board if you like.
Personally I think the Ehrenfeld hint looks most promising for now. I´m sure the shape based on a
traditional rummer shape would be german, austrian or bohemian rather than french or belgian, but I´m
always open to be corrected. Especially the trumpet-shaped stem seems to point towards that direction
IMO.
Datewise the slim and elegant dimensions of the stem are Art nouveau or later I think. As I said before I
can´t exclude a revival style. Hence I was suggesting Theresienthal, because they produced in older styles
over a long period.
However - if old indeed... Personally I find the one in the last link from flying free very close - but the one
on the very right even more than the other one, because the dimensions of the stem are so very close.
I´ll try to find more online.
Many thanks!