Wow, that is an old one, introduced in 1953. Evidently, they were important enough to be listed as an historic milestone for Pioneer, judging from a quick search online. If you can tell us more about them, that might help, but I think you have something that is sufficiently rare that it is going to be hard to know what they are worth. How many drivers do they have, and what size? How do they sound? What is their condition? I would like to see them and hear them, but I doubt I would want to actually buy them. But one never knows...
