One thing about the 23 is that it doesn't have a traveler. I can't remember, maybe later ones do, like maybe 1984. Anyway, this has been discussed lots of times here and none of us can devise a satisfactory way to install one in a way that doesn't really limit your cockpit configuration. Generally, it's my impression that the 23 is designed primarily for cockpit comfort, with the weird back stay mainsheet attachment and its overall simplicity. This works fine for me, but it's just a reality that it's not really got a lot of performance options.
Otherwise, the basic issues are there, as with any other 30+ year old boat; chainplates, bulkheads (which are not tabbed to the hull btw), whether or not previous owners have done the maintenance or just sailed on the hope that deck leaks would magically go away. Lastly, at this age, I'd be replacing the couple of thru hulls.