The San Juan 24''s were designed as IOR rule beating race boats. Rule beating is a design process where a designer shapes a boat and its
rig to have a good rating rather than to a shape that would be more ideal for sailing abbility, speed or seaworthiness.
While the San Juan 24 is a nice little boat that sails pretty well, the compromises that to beat the rule meant that they were a little tender (tippy) and also that their cockpits were a bit cramped compared to other boats that length.
San Juans were built to be ''value oriented'' and so were not the most robust of boats, but they were well built for what they were. A major concern is the age of these boats. I think they probably went out of production somewhere around 1980. That is pretty old for a lightly built boat in ''boat life'' terms. I strongly suggest that you have the boat surveyed by a NAMS or SAMS certified marine surveyor. While it is a little unmlikelt to be the case, the kinds of problems that could be present could easily be more expensive to fix than the entire value of the boat.
Regards
Jeff