Not sure of the method that was used to remove the plating. It is altered. The coin is in acetone to remove the corrosion I will post another pic later. there should be evidence of the original plating somewhere.
Here is an updated pick of the cent after acetone. My scale bounces from 2.4g to 2.5g. These coins are hard to verify even for the TPG's. They can be wrong at times. I think this one is self-evident though.
I think that the coin was subject to electrolysis. It shows as a dull coin even if circulated. The plating blisters are not a characteristic of a partial plated zinc cent, neither are the linear plating blisters. There is small evidence of copper plating on the 3rd side, mostly on raised areas
Ya know we used to have many folks that would treat a thread like this as an opportunity to teach, not for likes, just happy to pass on the knowledge that they have. If it is that we don't have those folks anymore, ones that will give their opinion of the coin, pro and con. Thanks to @Collecting Nut for saying that most Shield cents corrode and have problems, It's the same saying of every copper cent ever minted. Not meaning to point you out Collect but that was a short answer that jabbed at a legitimate find even if it is altered. It used to be Collective approach of opinions that made an answer, I miss it. Even if this is a Modern.
Can you post a photo of it next to a "normal" Lincoln cent? With the way cameras handle color balance, this coin's actual color could be almost anything. I thought you were just talking about the texture until you made the comment about "remove the plating"...
The thing about plating removal is that copper's so much less reactive than zinc. Harder, too. So almost anything that dissolves or removes copper will dissolve or remove zinc faster. I'm not sure how an electrolytic process could do any better. I'm aware of two chemical approaches. One involves cyanide, which is hard to get for obvious reasons. (I fuss a lot about access to chemicals being restricted, but not this one.) The other involves calcium polysulfide, which is easy to make, but stinks to high heaven. I might try the latter, but only when/if I can make it outdoors...
I quoted it wrong. Jason Cuvelier says Reverse Electrolysis in the article below. Diagnostics of Fake and Genuine Unplated Zinc Cents – CONECA