Need help with repair of my passenger side door lock located in the door (not in door handle) and operated by the external keyed lock cylinder. The door latch with external lock cylinder shown in the photo is from my late ‘30, 68-B Cabriolet. Rotating the lock cam with the external lock shaft no longer locks the door latch, indicating the locking cam may be worn out or broken. The externally operated square lock hole is in the lower left corner of the latch mechanism in the photo. Does anyone have a photo and dimensions of the locking cam that I can use to repair/restore my lock cam to proper size/shape in order to achieve working order? Any guidance in accessing the door lock cam for removal and repair would also be appreciated. Thanks, RLH