644-521-915-00-SET Seat Recliner Inner Cover Set, Gray for Passenger Seat with Locking Mechanism. Fits 356C and 911 912 1965-1967

Fun fact, the part numbers for these covers is sided per seat, not by where it is on the car.  So, 644-521-915-00 would be the left side of the seat, but could be on the passenger side of the car.  Same thing with 644-521-916-00.   So, technically, we could also call this set of two 644-521-916-00-SET 64452191600SET