they look like they are in really good condition for the age of these speakers. I don't know how far back they go but Audiogon has a blue book section for audio components that I have heard is pretty good, this might help tell you what they might be worth. But again I am not sure how far back in years they go for speakers. There are other sites I have seen that deal only in vintage gear and might be of some help as well, I wish I could remember the names of the sites but I can't sorry.