geez. Colonel Mustard in the Library with a Pinarello frame!

I think that is the remains of an aftermarket Shimano sticker. They used to (mebbe still do) give 'em away at races. I would not have thought that it would have affected the steel in the frame, which certainly looks like what happened. Maybe the last time the frame was refinished they bead blasted it with the shimano stickers left on???