Your shift tube looks pretty good. The levers must be worn. As Jimbare says put in nylon bushings. As you can see you have a grease nipple there. Remember to grease these afterwards yearly. This where people never notice the nipples and they tend to not grease the shifter levers. Thus the wear on them.
The crack in the frame all you can do is weld it. Make sure the weld is deep through the crack. Grind down again and repaint the area.
My Econo truck the frame has places where rust has come through. So part of my restoration of the truck is going to replace and patch those areas with new metal.
Areas the frame rust are at the front spring mounts, support bracket located behind the front wheels. Those brackets tend to rust out. Usually you can find one on a wreck that maybe good to cut out and weld in as areplacement.
Not much available for replacement metal on our trucks.
Good luck with the shifter aftrwards.