Mossberg 802 cocking piece

[Ritchie]

The cocking piece on my 802 has a great deal of play in it's channel. Sometimes the striker will not stay cocked if the bolt handle is not worked just right. The cocking piece appears to be a round button in a blind hole, there is no visible joint on the opposite side. It cannot be removed with a large drill chuck. I would like to replace it with a better fitting one. Gun Parts Corp does not list any parts for this model.
Possibly I could fit a collar to take up the excess space. Other suggestions are welcome.