This is a P.08 grip that is a S/42 replacement grip and was additionally marked with the HZaJt18 rework stamp.  I believe this was a replacement grip that was inspected by the Heerszeugamt rework shop for use in a repaired P.08.

This is an early P.08 firing pin (not fluted) that was inspected by a Heerszeugamt rework facility for use in the repair of a P.08.