On the 1996 cent both rims show very little copper platting. It also looks as if Lincoln's eye is doubled. The 1976 cent I am wondering what may have caused the damage? Thanks for any info.
Your coin is not an error; it is damaged. The rims are the highest points on the coin. The coin was probably rubbed on a surface enough to wear away the thin copper plating on the rims. Notice the copper plating is also worn away on the truncation of Lincoln's bust. Your coin is not an error; it is damaged. I have seen similar damage caused by someone dragging a coin on a concrete sidewalk under their shoe.