Now I know 1981 is a long time ago and the penny is obviously circulated, but when I magnify it, there aren't any signs of it being altered or scrubbed or damaged (other than the nicks you would expect from it being circulated) in the parts that are gone. So what are some other explanations? Grease-filled die? Anything else?
Might have been struck through grease (as some letters are basically missing) but it may have also been a very worn die...or both. An interesting piece but not worth much.
I wasn't alive in 1981. I know circulated stuff can get really banged up so... I think it's pretty neat, one of the more interesting ones from that jar. Thanks for the comments everyone!