Are you asking about rebuilding the pump, or replacing all the bushings, or rebuilding the power steering gear, replacing the hoses, or what?
Oh I wouldn't even bother. For the price of a reman it's not worth the effort. You can check rockauto.com to compare prices.
The bigger the pulley, the longer it will last too. Andy's absolutely right on when he recommends a reman.
Just wondering if there are companys out there that specialize in rebuilding the old Ford boxes...I recently had a box rebuilt for an old 1975 Scout II they did an amazing job but just specialize in Scouts.