Idler Lever ball anti-rattle ring?

[Praxiss454]

Hi folks,
Getting ready to button my engine rebuild back up. Cleaned off the idler lever piece which gets attached to the side of the block. There's a little ball joint, and in the ball there is a groove. In the groove there is supposed to be some sort of anti-rattle ring. Can't find this anywhere. What do I use?

Here is what my shop manual says.


And here is what my part looks like, with groove indicated.