For your consideration, here is a Oregon Coast Aquarium 5th Anniversary Souvenir Pinback Button, Pin, 1997, from Newport, Oregon.  It has a little wear on it and a little tarnish on the back.  The button has a diameter of 2 1/8 inches.  Item pictured is the actual item up for sale and comes from a non-smoking household.  (541.755v-.4px2)