Ghost

I found this mounted shorebird at a little bird sanctuary in Ellsworth, Maine. It is part of an ancient taxidermy collection that was donated to the visitor’s center. The gentleman I spoke to did not know the history of the mount or the identity of the bird. My heart skipped a beat when I first saw the mount, but now I am not so sure. The mount is in terrible condition with extensive foxing and ruffled/damaged feathers. Please give me your ideas about the bird’s ID and how you eliminated other species.