I gave up trying to fiddle about with the wire holder, as like you gold33, it never fitted that good and was a right skitter. I ditched it and used a couple of spots of araldite to hold the switch in. The switch fitted good in the hole and doesn't move side to side, the spots of resin are only used to stop it popping out of the hole, so doesn;t have much pressure on it. A few carefully aimed taps should loosen the grip of the hardened araldite it if I ever need to remove the switch.
John