Ironically enough, I just finished doing the same thing on my coupe! I had intended to post a few photos of the markings I found (which I will still do...hopefully tomorrow). On my coil springs I found a single pink stripe on both sides. The one marking I found which I've never seen mentioned before was on top of each spring perch. On each side I found a single wide green stripe between the bolt holes for the bottom of the shock. The dark, almost black, color of the spring that Charles refers to frequently was also clearly visible. The areas under the rubber spring insulator, at the top of the spring, protected the finish. I'll shoot some pics and get them posted for others to reference.
This car had a scheduled build date of June 11, 1966, also at Dearborn. It's a Sprint coupe with a 200 and C4 also!