Take them apart for rebuild is doable (I've done it) but... they certainly weren't designed for servicing. Then when you find a shaft is also very worn, you still need another pivot. The pivot has a bronze bushing in each end. Between them is hollow like a grease cavity. I think the bushing is 3/8 ID, 1/2 OD, and 1/2 long. I would need to go to the basement to confirm. I can say its standard/generic, available online. Search sintered bronze bushing for vendors.
