Aren't all the new ame grips including the Cams made from a completely different compound than the original 80's ones, they are described as being made from Vulcathane, which sounds fairly modern, on their site where as in old Ame ads they were made from thermo-flo rubber, which I think was softer.
So maybe newer Cams have a different feel to them, obvoiusly you'd need an old and new pair to compare the difference.