Well, I would think a true 5000-mile car should not need anything. Certainly spending any money on parts before you take it apart would be foolish.
First, take the cover off and look at what you have. The gears should not be polished smooth. From the factory, they would have parallel lines across the faces from the manufacturing process. The part of the gear where the sliding gears engage the other gears should have a slightly pointy and even face. The sliding shaft should not have a step on it that can catch your finger.
Look at the shifter forks for wear. Do the detents catch well when you move the shifter?
Look at the oil in the sun, does it have shiny spots from metal flakes?
If it does not look so bad and it shifts ok then put a new throwout bearing on and make sure you have the real correct oil in it. Do not try to make more work or spend more money then you really need to spend.
Les will have you put some oil on the spline shaft and see how fast the gears slide down. I measured the shaft and the gear mating surface and found I had about .001" wear and that failed his test, but is perfectly fine. If the spline shaft has a noticeable bump then it may be a bit too worn.
Some will have you add O-rings and seal bearings. The ****** will not leak more than it was designed to leak with the right oil. The shielded bearings will limit the amount of oil getting back to lubricate the U-joint. As for the roller bearings. I measured a pile of used ones and they were the same size and just a nice a surface as the new ones. I like to use original era Ford parts cause they seem to just work better.