Campagnolo 3x8 Bar End Shifters?

I'm not sure what I have here or what they're worth, and I'm hoping some of you can help me out. These are Campy 3x8 Bar End Shifters that seem to be indexed (they click at each number). They're in good condition as far as I can tell (although, I haven't cleaned them), and they function through their entire range. I'm wondering what model and era they might be as well as their approximate value. Thanks for any help on these!