Coin looks great to me, congrats on the purchase! I love the qualities of an earlier die state.
Copper coins are cleaned differently than other metals. Classic EAC collectors would use some Blue Ribbon and a horse hair brush to remove any unwanted material on a copper surface. Hairlines would not be visible like a wipe with a cloth.
Perhaps Verdicare or a similar product will remove the remaining substance?
Suffering from bust half fever.
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