Did all Chevrolet cars receive a OK inspection ink stamp on the AC compressor ? Or did that stop by 1971?

Hello LKS,
Not all the Harrison and Frigidare a/c received an OK stamp.Actually,it's my experience that the OK stamp was rarely used on a/c compressors.I have seen it on a few fuel pumps and on a/c firewall box.Maybe it was an A-body assembly check point thing. Jim