Merrill Hydrant Parts Kit - Pkcf Parts Kit/C1000 Hydrant

The Hydrant parts kit for c-1000 shows a plunger but does not include it as one of the parts of the kit. Is it there or not?

Will this kit fix a leak coming from the underground base of the hydrant? Water comes up from underground when the faucet is on.

There's an o-ring in the kit that has me confused. Where does it go. Didn't see one when I took it apart.

I see an answer from 4 years there is one that comes in the kit. Is this still true? Is there a reason why the description can't be updated after 4 yr