For your consideration, here is a Vintage Lot of 3 Vader Washington May Day Festival Pinback Buttons, Pins.  The buttons have some wear on them.  Items pictured are the actual items up for sale and come from a non-smoking household.  (675.11b24b-.4px2)

Here are the years, themes and condition notes:

1996 – Leaping Into May

1997 – Celebrate the Spirit Of Spring, has some light spots on the edges

2000 – Spring Into the Future