Perhaps there is someone out there asking what is this with a picture of that puller without that piece that you have. Post it up for sale.Guess it's time to either toss it, stow it on board just in case (you never know), or put it in the garage.
Never saw that on the 2 GB's I've owned. Only sure way to know what it's for is to throw it away. In a week or so you'll discover what it's for.
No - I have the emergency tiller