
The mark looks familiar, but from an area I'm not familiar with.
I don't think it is as old as art nouveau.
I've tracked down the first page of a glass marks lexicon provided by the great-glass website, all in alphabetical order. You might like to have a search?
http://www.great-glass.co.uk/glass%20notes/marka-c.htmReidel used marks similar to this, which they changed every year.
You're both already aware that Leerdam used marks in this style too.
Sometimes Dartington marks can be a bit like this.
But the glass itself looks absolutely nothing like Leerdam, Reidel or Dartington.
I'm quite confused and confuddled by it.

Welcome to the board, Elsie. Not everybody logs in every day, don't give up in despair after just a couple of days. Some ids can take time, (some years!) but we don't give up.