Same as you would with any old boat. Check the
hull,
deck, bulkheads, chainplates for
water incursion from rain leaking, for
delamination, for
rot. 30 year old standing rigging, and any stainless fittings with it, are due for replacement. Masthead fittings, sheeves, bearings, all need
inspection. Everything needs to be surveyed, unless you know the boat was put away new and has been
on the hard for the last 30 years.
If the
engine wasn't pickled, the rings may be frozen in the cylinders. If the
cooling passages weren't blown dry, there may be freeze plugs blown out.
Exhaust not plugged? There may be bug nests in it. Everything still needs to be checked, and the odds are the
fuel tank/system need to be cleaned out as well, if that wasn't prepared for
storage.