Good subject with great timing. I have what is thought to be the original calipers off of the 71 Chris and I have owned. I have been trying to determine with any amount of certainty if theses are indeed original. It seems difficult to find any definitive information,
I did see this on the Yenko.net website when I was researching......
https://www.yenko.net/forum/showthread.php?p=1085882
Left side caliper