Glass Chatroom Board

While I'm here: I've asked about this piece in several groups - and I'm interested in what the folks here have to say. It's about 18-20 inches high. The cord and fittings (except for the socket) are "older" i.e., 2 prong cord, brass (or what appears to be brass) fittings - can't unscrew it. No markings anywhere.
http://www.pixclix.com//susan/glass-lamp_1.jpg
http://www.pixclix.com//susan/glass-lamp_2.jpg
http://www.pixclix.com//susan/glass-lamp_3.jpg
http://www.pixclix.com//susan/glass-lamp_4.jpg
http://www.pixclix.com//susan/glass-lamp_5.jpg

I'm trying to help a friend ID this, or at least find a re-sale value. Thanks in advance!!!

Susan