According to the vendor he was the lucky recipient of this broken piece of drum kit, thrown into the crowd, at the end of one of Nirvana's concerts.
The Tama Granstar (Silky Yellow finish) drum kit, owned by Grohl since his high school days, was used in the recording of Nirvana's seminal album Nevermind, released just a month before this concert. Significantly it was on this day (12th Oct. 1991) that Nevermind debuted on the Billboard album charts at no. 144, and the day that Kurt first kissed Courtney!
Dave Grohl joined Nirvana in 1990, replacing Chad Channing. Grohl's style as described by technician Miles Kennedy: Just by playing so hard, he'd break drum thrones, there were just piles of sawdust on the drum riser from his drumsticks. He was just an animal. Kennedy recalls the drum kit being smashed set: There was nothing left any bigger than a six-inch circle of wood from the kick drum [this piece is significantly larger] That's just what happened when they got so much energy and emotion worked up playing their set that it was the only way they could come to a good close.