That is awesome! As someone said, that has not been in the wild its whole life. I'd say that no matter what, if you got that for 1 cent it is the deal of a life time in terms of return on investment! Since you made such a great find with your son I would of course hang onto it. Financially it might not make sense to grade it but it may be a fun exercise to see how your grade stacks up to the professionals. I've seen a lot of people on this board play "you vs the TPGs" for fun.