Gidday,
Jagarra I just fitted up the spring/ball combination to the switch and it now works a treat mate
I undone the switch, then I put a metal catch tray just underneath the working area, hung and tied that off so that it sat level just below the bars and then I draped a few towels over the bike and funnelled them down into the tray so that the ball would roll down into that each time it fell out while trying to install the ball, the spring would stay put but the ball would drop out and this time none went flying across the resto shed and never to be seen again
After about 30 minutes and a good few attempts I was successful and all is as it should be once again.
Thanks heaps for the spare parts and for posting them asap.