I haven't tried cocobolo myself yet. But from its sound I must recognize it's pretty impressive. Gotta get a barrel.
I don't really know if a 70s topline Buffet clarinet could sound better than a 2013 topline Buffet, but from what I know about electric guitars I can definitely say that there are periods when Fender (stratocaster, telecaster or any other model) were much better than in recent years. No one really knows why. It could be anything. The wood, the machines, the people working on them. There are some mexican Fenders from the early nineties which are almost as good as the American ones which cost double.
I have an American Fender. I've tried many from many different periods and each of them is a different quality. As I said before recent ones are not the best.
I guess there's not that much information about the periods when Buffet clarinets were worse and better since there must be 10000 Fenders for every Buffet, but I wouldn't be that sure about the relation between quality and closeness in time. It's not like cars, you know? In case nowadays cars are better than classic cars, which I'm also not very sure about.
"Just to reiterate my position, I think that "professional" is supposed to mean, "This is the best we can make." "
That would be the definition for topline (Prestige, Tosca). I consider r13 and RC to be professional, but not topline. No one would think about RC if you say topline. They would think about Prestige, for sure.