Throttle grip anti-rotate nub(?)

Hello all

So I have this issue with the throttle/kill switch/start button housing
. Usually there is a little nub on the housing that mates up with the hole on the handlebar as an anti-rotating measure. As you can see in the included pic, it has been sheared off.

I'm sure other people have seen this as well. I have a new housing from the Bay but alas, this one is sheared off as well.

What is your recommendation to alleviate this?

Thank you so much