Digikey has replacement Switches for the trigger and other buttons.
A long time ago someone posted the part numbers.I wrote them down.If I can read what I wrote here they are.
I have not verified any of these.I only put the info in my archives.
Trigger Omron B3M-6009
http://www.digikey.com/product-searc...omron+b3m-6009
Hat(4 pieces) Omron B3F-3122 (150g)
http://www.digikey.com/scripts/DkSea...=0&y=0&cur=USD
Switches 2-4 Omron B3F-1002(150g)
http://www.digikey.com/scripts/DkSea...=0&y=0&cur=USD
Base Omron B3F-1002(150g)
http://www.digikey.com/scripts/DkSea...=0&y=0&cur=USD