I believe the tranny case is a replacement. Since it has CC0 stamped into it, it is a over the "Counter Case" and the zero after CC is for '70. Check your case casting number and see if it ends in '661. They started using them in the later part of '69. The '660 case was used in '68.
The number 41685 is the serial number of the case not of the car.
Replacement cases do not have a date of assembly stamp since they were not sold as a complete tranny.