I could use your help!

I'm up very early this morning. The sun is just coming up, the house is so quiet. Even the animals are sleeping.
I've been hunting around this stste of Rhode Island for old, vintage beads. They are so different and more exciting than new. There is an old factory building in the Onlyville section of Providence where the old jewelry district was, it's run down, dirty and I love to go there. You buy old beads by the pound, truely. It's overwheming. They have rows and rows of beads, the hardest thing is picking out what you like best. Take them home, wash them, place them in a bag, and look up what they are exactly.
My question. How do you really know what is vintage and what is new? I know they are Czech, they are marked..but are they truely old??
Does anyone have any information, websites, tests that I can do more research finding out how old a bead is??? a book?? a magazine, article? I could use your help.
Visit my Etsy shop, look at my supplies or leave a comment for me with any information.
Thanks.
www.debsdesigns401.etsy.com