If it's leaking oil badly, you need to check the condition of the bearing housing. If the bearing is bad enough to allow considerable sideways movement of the shaft, chances are the housing is buggered too, so new bearings won't help much. If in doubt, get the cartridge.
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!