In my opinion this is a damaged coin. Keep looking there out there. Study on the minting process. What kinds of errors happen at the mint and how they happen. Good luck and happy hunting
So how does a coin get damaged with the imprint of the word (one) stamped sideways on the reverse? Damaged as in ...when it was made?
Correct. Vise job. Intentionally damaged after it left the US Mint. Why? Only the person that did it would know the answer.
Another cent was placed against this one and squeezed, this pressed a backwards "ONE" into this coin.
Creative bored people with vises! "hmmmm, what do I want to do....I think i will go out in the garage and smash two pennies together". Maybe he was pretending he worked at "CERN".