I found this Cent earlier It looks like a Class VI DDO. I went on coppercoins.com and couldn't find a reference. Excuse the heading I meant Class VI, thanks to Non_Cents.
Class IV would be an offset doubled die. I think you are referring to class VI (extra thickness). To me, it looks like you coin took a bunch of hits that flattened the design. Could you post a pic of LIBERTY?
I agree with Simon. It looks like circulation damage which often flattens letters and devices. Notice how the numbers are flatter and not as rounded as they should be. On class VI doubled dies, even though the devices are thicker than normal they still have the normal "contour" and surface elevation if that makes sense.
the numbers are rounded and Why isnt the 1 flattened? Its just my opinion but I find it hard to believe that 964 is circulation damage. its just too wide of a spread and too thick and also look at TRUST and IN, and look at the R in LIBERTY not to mention how smooth the surface is on 964 I think if it where circulation damage It would be alot more beat up.
Seeing LIBERTY, it definitely looks like circulation damage. Metal is very very malleable, especially copper. Consistent damage can definitely produce the effect that you see. The metal has been spread and looks flattened...not in the sense of the flatness you see in MD, but that the metal has spread thinner as it spreads out. This is definitely apparent on the date. The letters may be wider, but they do not demonstrate the same extra thickness of a class VI doubled die. Re-read Jody's post and try to understand the relationship between extra thickness width-wise and extra thickness in elevation from the coin. Your coin is extra thick wigth-wise, but the design has a lower "elevation" than normal, indicating that the extra thickness comes from the coin being flattened, post-mint.