Wouldn't there be acid etching on the remaining of the copper? I've never dipped anything in acid before to know. Also, there is a lot of luster on the copper parts.
Look closely at the third pic, notice how the steps disappear under the spots. You have a coin covered in paint.
No, the coins are not copper plated they have a light copper wash. I've seen pennies dipped a few more seconds and they come out looking like they never had the copper wash at all because the detail is all there; my young grandson calls them silver pennies.
