Okay Well I have this penny 1998-D It looks very corroded but the interesting thing is that on the obverse and reverse side it looks like the clad is gone idk like a grey color but on the edge of the coin it is still copper toned..
Somebody messed with the coin - they removed the copper clad layer on the obv & rev but not on the edge.
As you might guess, there are instructions for almost everything on the internet. Search and you can find methods of how to remove the copper from the zinc with small effort. I was surprised at first, but it makes sense with all that show up. Didn't seem to mess up the zinc layer at all. Jim