Ok.
The first version used 2 brass pins set into the grip edge.
Drawback was that the grips had to be thick at the edges to provide enough mass to hold the pins.
The second solution was to have a central pin in the frame which would retain the grips. Cheaper to do and allowing the grips to be contoured better.
With age, the grips dry out and develop some play around the retaining pin.
So both solutions eventually proved not to work well. At least they tried
and it was not a short cut.