I would go down to the hardware store (like ace/truevalue) and just drop in a ball bearing that doesn't fall through. Then find a spring that is light or stiff enough to work. i would use a cut and stretched pen spring. Then use some kind of epoxy or even hot glue to tack the spring to ball and then to cover.
We used to this to our VS2's as they came with large holes for soft detents that constantly just blew out. Ball bearing mod is great for actual play.
something something something
I'm all out of ideas again and this text is so plain.
I'm still not sure how I feel about this new look.