Spend years discovering the history and previous owners of the coin . Do every non destructive test possible... and if it is fake ( which it will be).. AT it and sell it on ebay
If you find a 1913 Liberty nickel, you should study it and see whether you can determine on your own what kind of fake it is, then take it to a dealer to check your work. You'll gain knowledge and understanding, and that's where the real value lies. One of the big lots of V-nickels I bought a couple of years ago included a 1913-D. I really need to get around to posting pictures; after all, it's my very first R8.
I would take it to a major show like the Fun Show and hand it to PCGS in person. Next, I would call Mark Feld with Heritage and ask his opinion of my next step. After that there would be a great party.
99.9999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999% chance it wont happen. I would rather be prepared than panic and sell it to a coin dealer for $200,000 . or sending it In to grade it, and it never comes back...... (this is all based off it being real.)
Why would it not come back? Are you trying to say that the TPG would switch out or steal your coin? Just as with this whole "what if I find a 1913 V nickel" thing, this too is not going to happen. The coverage and bragging rights of certifying the 6th specimen would be just as valuable to the TPG as the coin would be to you, not to mention the risk of ruining their much more valuable reputation and business to steal a coin.
Amateur savant ... Comet - it makes your teeth turn green; Comet - it tastes like gasoline; Comet - it makes you vomit; So take some Comet and vomit today!