The strand is definitely freshwater, and there is no chance that it is vintage. You can see by this auction as well, anything that is large is an 11-14mm South Sea. The graduation is certainly not 11-14mm on either.
http://cgi.ebay.com.au/ws/eBayISAPI....m=330083868941
I do not know enough about the other stones things the seller is auctioning off, but I know enough about pearl to know that these two strands are less than 10 years old, certainly not the antiques advertised.
http://cgi.ebay.com.au/ws/eBayISAPI....m=330082124090 http://cgi.ebay.com.au/ws/eBayISAPI....m=330085243068
The art deco stuff may be fine (I defer to our collectors here), but stay away from the pearls.