I recently came into possession of a silver coin that says .999 1 troy oz. It has Washington's head on one side, "father of our country" on the top, his name on the bottom. The other side says "250th anniversary" with an eagle facing left and a banner over it saying 1832-1982 - obviously that's only 150 years. The bottom says RARITIES.

I have searched high and low online and the only thing I can find is the 250th anniversary GW HALF dollar, which is not the same thing. Does anyone have this so I can confirm its value or authenticity?