Well I can tell you that your plant is indeed very old. See the curly, corky-type central spines? Those are the adult spines, as Turbs tend to have two forms of spination: the juvenile spines and the adult spines. Since all you can see on that plant is adult spines, then i'm guessing that plant must be, at the very least, 20 years old, and it's very likely that it could be 30 years or older, especially if it has been grown in less than ideal conditions.
It's an oldie, for sure.