*possible *possible. That is some major nice doubling right there, that's not possibly ddo that is the definition of ddo. nice find.
It depends on the cost of grading, and how much money will this coin bring ungraded and graded. How much is this DD coin worth? It would have to be enough to be worth grading. If you are keeping it and not selling it, you may want to have it authenticated as a genuine DD regardless of the cost. If it is worth a lot of money (I don't know, you need a World Coin expert) then it would be worth getting graded. If it's not worth that much, then it isn't worth getting graded. Cool looking coin.