I modified the 1-switch teak grip with a second one. The pre-carved grip came bored for the switch at the top. I rasped the hollow for the index finger to a small flat and bored a hole for switch no, 2. Black heatshrink around two wires from the top switch. Clear heat shrink around all 4 wires from the 2 switches. Both switches are normally open momentary push buttons. One is pilot's PTT, the other is A/P disconnect, but I haven't decided which one will be which yet.
The switches are a friction fit in the bore--at least for switch no. 1. No. 2 is a little loose, but the foam packing (image 3) keeps it from popping out.
I also drilled to small holes at right angles near the base of the grip & installed brass inserts for 4-40 set screws to secure the grip to the stick, but easily removed for future maintainence.