I have carried out the SIDS on several 152's and the only real corrosion issues I have found personally was behind the wing cabin air intakes where moisture had got in.
You have to remember a low houred aircraft is not always the best as it may well have been sitting in long grass outside etc and any moisture build up will not have had a good airflow through the aircraft to get rid of it, which a regular flyer would have, same goes for the engine, an engine needs to be operated at regular intervals to ensure a good coating of oil on the internal surfaces and again to dispel moisture out of the oil, ground running incidentally may not achieve the latter as it never gets fully up to operating temperatures.
Sids like the wing attachment will need the wing mounting bolts pulling for NDT inspections of the holes, I as a matter of course replace the stiff nuts and bolts with new when doing this, it makes sense as they could have been in there for years.
But our aircraft are regular flyers and they get the maintenance they need, items like the aileron control hinges have all been changed over to the later pin design, you will have to factor in the costs of items you may need, generally Cessna parts are not badly priced, but they do have some that for some strange reason appear to be priced at space shuttle costs.. the piano hinge for the elevator trim tab on a 152 will cost north of £1000.