Campag overhaul for a 9 speed bike will = remove BB, check size, send to scrap recycling, order new one (if you haven't already) fit and ride.
They are sealed units, nothing to overhaul on them, other than replace.
For liketime, have had one fitted since 2000, pulled it a few years back when re-finishing the frame, and apart from a little surface rust, was smooth as new, still is, and it's done more than the distance you have on yours.