It is in homage to Woody Guthrie that the sandal wearing, fair isle sweater adorned British folk club regulars used to put such things on their guitars. You could buy them as stickers on trade stands at folk festivals. Singing about saving the world at night probably made up for having to stock take pencil sharpeners during the day.

Sorry, I keep making the mistake of aiming my posts above your head. In this case , a few thousand miles to the east too.