Things such as prices can get weird on Ebay. For instance, I worked at a music shop and was given a beat up Fender Bandmaster head. Now I want to be clear of a few things. It was just the wooden part of the head, no electronics. It was also beat to crap. When I posted it on Ebay, I made sure to let people know what bad shape it was in. But I did have a picture of the inside where it showed all the Bandmaster info and schematics. That way, people knew it was for real, just in bad shape.
I figured if I could get $10 plus shipping that would be a win. I mean, hey, it was given to me for free, right? The bidding ended with it selling for $80 plus $20 shipping. It shocked me. Just a head, no electronics, and I described it as being a negative 2 out of 10. (Yes, I really did say that.)
Since it has that magical Gibson name on it, you could get a very surprising price for your tailpiece. Good luck in whatever you decide to do.