For your consideration, here is a Mount Saint Helens May 18th 1980 Eruption Pinback Button, Pin. It has some light wear on it. There is some tarnish and the remains of a price sticker on the back. The diameter of the button is 3 inches. Item pictured is the actual item up for sale and comes from a non-smoking household. (257.308f-.4px)
[Thanks for looking!]