Amazon refunding on watches

Hi,

I’m especially selling classic watches.

And ofcourse we receive returns as well. But some are ok to sell again, but sometimes people have worn or shortened the watch, which we now can’t sell again as new.

Now I do now that we have the option that we can refund just a part of the purchase price. But does anyone else has experience in such returns? If so, how to handle returns that you can;t sell as new again?

Thanks in advance.