Thanks all. I still have the original grips so maybe I'll use them as guinea pigs to see what works best. I did think about safety wire but they are pretty stiff grips and I'm not sure I could get enough pressure on them to hold well without cutting into the grip - which might cause more problems; internal wiring and all.
"If ever a time should come, when vain and aspiring men shall possess the highest seats in Government, our country will stand in need of its experienced patriots to prevent its ruin."
- Samuel Adams