I am not familiar enough with this boat to accurately comment. Ask people that own it, and know it well...they will be the best source of info.

In my experience, old sails are often powerful in moderate breezes, but are often hard (or even impossible) to trim. This is due to the chord (depth) of the foil shape being 'blown outward' with time-they do lose shape over time. Such sails can be fast, sometimes overpowering, in a fresh breeze, but painfully ineffiecient and slow and horribly ineffective in light 'drifter' breezes. As for general technological improvements, I think sailcloth and shape, and constancy has generally improved over the years.