What to do with Treasures among the Scrap

What's the right way to handle this? Let's say you were removing iron/misc; maybe cleaning out an old building or a complete farmstead and selling the metal scrap for a percentage of the take. You find something that is definitely not junk and would like it for yourself or for resale. For example a new CB antenna still in the wrap that the owner obviously didn't want or maybe forgot. Do you offer to buy it from the owner, close your eyes and leave it in with the shred, go to the bother to take it home and put it on Ebay and share the profit with the owner (and then if it didn't sell, you're responsible for the antenna and owe the owner at least something)....or throw some of your own scrap in with the load to make up for the weight and take it home as your own without saying anything?

I run into that all the time and I usually show the owner what I want and pay more than scrap value....how do others handle it?

Thanks