Here is a list and picture I found on an XCR forum for suggested spare parts, the only thing that might be different deprnds on what type of firing pin you have.
Firing pin
Firing pin spring
Extractor cone
Extractor spring
Firing pin roll pin
BHO Shaft
BHO pin
C Clip
Ejector
Ejector Screws (2)
Hammer Axis pin
Cotter pin
Hammer spring
Ejector washers (2)
Main pin
Recoil buffer
Trigger axis pin
Trigger spring