Does not matter what the damage is, you found a piece of history and rescued it forever. Now, sit back and wonder who lost it, what it might have purchased at the time and how disappointed the owner was at losing it. Any find this old is amazing!
Are you kidding me lol!!! That looks like it is in mint state compared to some of the coppers that I have found!! Half the time I can't ID a type.
I know how everyone hates to clean a coin but in this (I) would because under all that crust may be enough to ID it and that's where the history kicks in and the imagination begins.