1969 /70 vs. 1971-73 A/C control cables

I wonder if anyone can help me with this situation. The MPC shows two different A/C control cables for these Cougars : 1969 /70 calls for C9ZZ-19988-A and the 1971 - 73 Cougars show the applicable cable to be D1ZZ-19988-A.
When I look for the correct cable for my 1969 at WCCC I get the C9ZZ cable to be used by all Cougars, 1969 through 1973 - and no reference to the D1ZZ version. Same thing if you ‘google’ the C9ZZ vs. the D1ZZ - you come with references to the C9ZZ ( for all Cougars 1969 - 1973 ) and nothing on the D1ZZ version !
Is it as simple as the C9ZZ would fit all the years 1969 - 73 and even though a D1ZZ is listed in the MPC, it wasn’t sufficiently different to prevent the use of the C9ZZ for all years ? What would have made a D1ZZ cable different so as to warrant it’s own, unique part number ?
Can anyone shed some light on this ‘conundrum’ ?