Could someone please point me in the right direction. I have a bash on Sunday with Nitronorthwest and I need a few spares.

As you know, the ATX has a 2stage gearbox. And in the gearbox is 2 spurgears, both red in colour. But I have stripped the clutchbell of it's teath. I dont know what tooth it is could someone please help me out? And I've ruined the Pilot Shaft also. Could someone tell me where I can find these please?
Thanks
Karl