I'm not sure it has been cleaned , those green spots look like verdigris to me . Best to have the verdigris removed before it damages the surface .
I agree. But it is a nice coin, and I doubt you will ever find a nicer XF overall. Could be a bidding war, or just two bidders who appreciate quality within a grade range. Some people try to put together a matching set, and this would be a superb XF example for such a set.
It is kind of like the AU-58* CAC/MS-61 complex? Otherwise would we rule out that the seller of this coin might have been bidding up the price?
' I've never dealt with any verdigris , but I hear acetone , the pure kind you can get at hardware stores , is the only kind you should use . I'd ask people who've dealt with it on copper coins though before using anything . Thad a member here sells or used to sell verdigone , you can get it from Wizards , is suposed to be pretty good . Plus I've heard mineral oil or olive oil would work . You could start a thread asking for opinions with a pic of your coin . Good luck it's a nice coin .
Please stay away from mineral oil and especially olive oil. Olive oil will permanently darken a copper coin.