What's Wrong With My Balance Staff?

This belonged to my Grandfather. It's a large scale, plastic model of a balance staff including a number of interchangeable pivots and balance hole and cap jewels. It is intended as an aid in showing a customer what is wrong with their watch.

The interchangeable pivots include a bent one, one worn to a tapper, a broken one, etc. The jewels likewise include holes and caps worn in all the various common ways.