I bet if you could get an accurate measure on the diameter of the pins with a caliper, that someone here could tell you whether or not they are oversized. What makes you believe that the pins have been replaced ever? They may have never been touched.
If they havent, and the hole isnt warped or worn through the bushings, then youd be perfect for a new set of kingpins in which a machinist would ream the bushings to fit the pin.
Hope that helps.
Jeff
