For your consideration, here is a Vintage Make Mine M*A*S*H Pinback Button, Pin, from 20^th Century Fox.  It has some wear on it.  There is tarnish on the back of it.  The button has a diameter of 1 5/8 inches.  Item pictured is the actual item up for sale and comes from a non-smoking household.  (677.12b22b-.3px2)