My recollection is the paper gaskets were released as part of a service fix for a small batch of manifolds that were mis-machined and the manifold to head face not in the same plane. I'll look and see if I can find the service bulletin. I think if you look at any of the factory packages you will see a date after June or July of 1969 That's why you likely will never see a factory built vehicle with the gasket. I have personally seen no less than two factory manifolds out of flat by over .015".