For your consideration, here is a Lot of 3 West Seattle Hi-Yu Pinback Pins, from Washington.  They have some wear and tarnish on the backs.  They all have a diameter of 2 1/4 inches.  Items pictured are the actual items up for sale and come from a non-smoking household.  (558.984g-.5px2)

Here are the pins, with the year, theme and additional condition notes:

1991 - Undersea Fun in '91, has some spots under the clear finish

1997 - All That Jazz

2001 - Storybook Summer