It looks like one of those coins beat with a spoon to make a ring. You could try googling spooned coins. It could also have been in a water pump or dryer for awhile. It does look heated. I had some pennies warp up from sitting on my dash in the Florida sun. http://coinauctionshelp.com/page15.html
I wouldn't mention more than a little of the mysterious circumstances of it's discovery,
but you could give it a run on evil-bay and perhaps get a fortune for it !