For your consideration, here is a 1981 Great Lakes Forestry Exposition County Centennial Mio-Mich Pinback Button, Pin, No. 631. It has some wear on it. There are some tarnish spots on the back. The diameter of the button is 2 1/4 inches. Item pictured is the actual item up for sale and comes from a non-smoking household. (263.312g-.4px)