1983 Lincoln Cent Error?

Bottom half of "S" is gone as well as the "E" in e pluribus unum.

I agree. This area is known for weakness because of the strike on the obverse side, leaving a weakness on the strike of the reverse. But these letters are showing a difference in the size of the devices like the die was wiped with a cloth. Leaving more great in some areas and uneven amounts in other areas of the die. Note how this changes on the diagram below where partial Grease Fill happens on some devices from a die being wiped with a cloth:

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