Chris, reread my last post. Those old Kodachromes were already deteriorating after just over 40 years. I've noticed that in some of my other Kodachromes as well. Something I can't explain since I always believed Kodachromes would last longer. But nothing like the old Agfa and Fuji slides. They have faded badly.
But nothing is forever. We should enjoy what we have while we have it.