Norman,
Since you're using bluewin, I guess you're located in Switzerland.
As a regular visitor to Swiss antique shops and Brockenhaus, I'd say that much of what you find locally will be Swiss, German or Austrian, although there is a fair bit of bolshevik glass, too

.
Quite a lot of glass was produced by Swiss makers over the years, free-blown pieces, and also poured, pressed and slumped stuff.
Are you familiar with Sarner Cristal or Hergiswil? If not, I'd try and get hold of their catalogues, especially any older ones you might come across. Might well answer a lot of questions such as this one. Sarner now only produces fairly unadventurous tableware, but Hergiswil is still quite prolific.
Cheers,
Chris