Ray,
You opened a can of worms, so let the squirming begin. I have a coil date coded 5CDC (fourth week of March. 1965)sitting on my desk that has become a semi-permanent fixture. I don't know plant or car type it came from, except to say that it was a Mustang and, as the majority of Mustangs in the San Jose area were built in Milpitas (the actual city where the plant is located), I assume it's a San Jose car. The coil's identifying stamp was wet when the bracket went on and there is a mirror image on the bracket. That includes the date code.
The bracket has the hole, angled at the top right for mounting, but the coil has no alignment dimple. It is painted semi-gloss black but with more gloss then the coil. The mounting bolt, 378604-S8, is clear zinc for 65-66. It should also hold the dip stick. Shelby owners will maintain that their coil brackets are natural steel, so let them jump in.
My Oct 65 build "K" Fastback is the same as above, but I cannot verify that it's the original.
Jim