I believe that each previously owned boat should be viewed as an individual case. The only thing that certain models truly have in common are the original design. After that many things happen to the boat regarding upgrades and or the lack of maintenance.
I would strongly suggest that you get a copy of Don Casey's Sailboat Maintenance Manual and follow his guidelines for doing your own personal survey. Then if the boat still fits your needs and looks good for the price, hire a good surveyor to look it over.