Ok, 67 changes/oddities rear their head again.
I'll update my post above.
But based on the Very Early Wiring post it appears we have some different labels and colors.
We have a February 67 Dearborn car with C7ZB-17664-A under a black FoMoCo script in an oval.
A September 66 SJ car with no part number and red FoMoCo script in an oval.
An October 66 NJ car with a C7ZB-17664-B and a black FoMoCo script in an oval.
Maybe my March car DOES need a C7ZB-17664-A with FoMoCo in an oval.