Hi,
I agree with Steve in that it could just be the lighting.
Last night, I took photos last night of the same coin using a different lighting method - placing the light source at such an angle that it bounces straight up into the lens as though originating from there (axial lighting). This lighting technique makes silver coins look like "proof" coins: the tiniest imperfections stand out but on the plus
side all details including legends are much clearer.
If I get a chance later today I will post a couple photos to illustrate how different the same coins look using different lighting set ups.
The second photo below uses softer indirect lighting (less constrasty) which can obscure details.
Of course without the coin in hand this is just speculation!
Have you contacted the dealer and asked them to confirm if the
graffiti and other marks are
still present? Or to send you additional photos?
Peter