Hello all! Thanks for your great and encouraging comments :)
That squiggly line from the Y was puzzling me too, its not raised nor is it a scratch. The closest thing I can liken it too is a carbon streak, but it follows the sort of line that I would expect from a die crack. Moving from raised point to raised point...
Perhaps it is a worn die crack? But I dont know if that would leave a visible line such as this.