For your consideration, here is a Seattle Eastside, I Write For Bumper Weekly Pinback Button, Pin.  The button has a diameter of 2 1/4 inches.  It has wear on it.  There is a little rust showing through the front of it.  The back has some light tarnish on it.  Item pictured is the actual item up for sale and comes from a non-smoking household.  (694.7c9d-.3px1)