I have been looking into the tradition models with the grey anthracite movements, specifically the 7027.
I found a used one in a local store, and upon inspection, I found several parts of the movement becoming discolored to dark brownish hue around the edges (which made me hinder from buying).
I thought this was due to some unusual abuse, possibly through inappropriate treatment upon overhaul.
But looking through photos on the Web, I found other units with similar discoloration, such as this one: