oops small mistake DOT codes came in the 70'sNo I do not believe after market installers could install glass the same as the factory at that time.
It would take someone with a DOT coded glass installed with the factory seal in a pre DOT car for me to believe it.
Say what you will but the Shat-r-proof glass is going back in the car as everything found to this point indicates it is the ORIGINAL factory installed piece.
DOT markings may not have been required until the 70's however I had a 45 k mile april 1969 Z28 Legend certified original paint car with DOT bugs on every glass.
I have read the report many times I have also removed tons of glass and have never seen a factory type seal used in conjunction with an after market glass, as an aside I know what the abbreviated installation looks like and this seal was never cut.
What is the earliest appearance of DOT coded glass in a 69 model year Camaro?
When glass was going from non DOT to DOT coded there are any number of things which could have happened.
BTW the report states LAMINATED was a STATE MARK from historic state requirements not a GM required mark.