Have you tried the Dutch glass museum search?
http://www.nationaalglasmuseum.nl/At the top of the page, where it says "zoek in de collectie van het museum" you can fill in your search terms (in Dutch).
If you click one below the open space, on 'uitgebreid zoeken', you enter the extensive search module. You can refine your search by designer, period or type of object (in this case, your object is a 'vaas'.
Personally, I'm not sure it's Copier or Leerdam (but I don't know that much about Dutch glass). It's a bit ... curvy. It could be Scandinavian or German, or perhaps even French.
If it is Dutch, luckily there are other people on this forum much more qualified to have an opinion

Astrid