Thanks to @hosejockey61 I got the nerve to try and rebuild a saginaw steering box. I started disassembly tonight and ran into my first potential issue. The sector shaft has some wear at the area the bearing rides. I can barely catch it with a finger nail but it's there. Replace or clean up and run it? Pics included.
Try cleaning it up first and see what it looks like. If all else fails, a used box at a junkyard is around $40.