So a few months I picked up an interesting find at a local antique store that I know the description wasn't correct but I've seen these in books but never in person. This Buffalo nickel was labeled as an error coin but the mushy details and lack of obverse of the coin leads me to believe it to be a contemporary counterfeit. I would say it wasn't to deceive the coin collector thinking it to be a rare date or a one sided error coin but to pass in circulation without being noticed of counterfeiting. At the first glance it appears to be a genuine coin but the color just isn't correct leading me to believe it's made out of a different metal.
I agree with Rothery. Why go halfway on the counterfeit? The obverse looks like a slug.
Looks like the obverse was ground/filed/sanded off.
Underweight. Plus, in the photo, I believe I see zones with lots of parallel scratches, and the direction of the scratches changes from one zone to another. That is exactly what happens when you try to grind something flat and change cutting direction and don't apply pressure consistently while shifting things around.