If the zip was 17003, covers a pretty wide area. Shack is more likely to have been north of 422 but could have been in North Londonderry, North Annville or East Hanover Townships. If you know the years he lived in the area, and he owned the property, try doing a name search in the tax assessors office at the county courthouse. Helps to know the road he lived on. Post Office does not keep records of past residents.