Rare Camp Billy Machen Navy SEAL Challenge Coin , I received at the camp. Condition is carried, but Great Condition. The item “Rare Camp Billy Machen Navy SEAL Challenge Coin Devgru” is in sale since Friday, December 21, 2018. This item is in the category “Collectibles\Militaria\Current Militaria (2001-Now)\Original Items\Challenge Coins”. The seller is “rio_gato” and is located in Conroe, Texas. This item can be shipped to United States.