1983 Kennedy Half Error ?

Those marks are from a die clash. This happens when a die pair comes together without a coin between them, some of the obverse and reverse patterns are superimposed on each other. Coins after this die clash show the marks where they hit on the highest (lowest relief) parts of the dies. This is a very nice clash, the marks are very clear, you don't see alot of them this clear and severe, this die was probably polished soon after or retired.

Personally, I like clashes- especially when they are so clear as this one. Some say they don't carry a premium, I would pay a premium for a coin like that, so it is definitely a keeper . Nice one !

The scratching is probably from polishing attempts. Alot of people here search rolls of halves, myself included. I have never found one with clash marks that severe, I am sure others might have.

There were no mint sets made in 1982 and 1983 so I tend to keep most every half from those years unless they are damaged. That half looks to be in pretty decent condition along with that nice clash. Since you say you have more, when you reach 50 posts I might be interested in acquiring one. Thanks for sharing !

Clashes like this one on a larger denomination coin generally do bring some premium value - best to check in with someone who deals in this sort of thing to find out what a realistic value is. I would assume north of $10 for an uncirculated example.