The part number for the switch button is 68846 and the base for the stop switch is 215320 (I have this in stock).
To be able to replace the switch you will have to remove the shaft from the motor first then remove the rubber grip on the shaft and then you will be able to take off the throttle/switch.
Regards,
Bruce
Please do not PM me asking for support. Post on the forums as it helps all members not just the individual.