Hi. I bought this today, it caught my eye and was at a very reasonable price. My initial research leads me to believe it is a U.S. Centennial Exposition 1876 medal, the gilt variety HK 22.
I've included a scan of the piece, which frankly doesn't do it justice, it looks so much better held in hand, i'll try get some decent photographs. It is 37.5mm and 23 grams.
Does anyone know anymore info about this interesting piece? or perhaps what its approximate value might be?

