The clip pin is not a big deal. I usally carried a spare just in case one got "lost"
The thing to check on the ball is if it is the correct weight range. Sometimes they were replaced in a pinch with an underrated ball. If you are too concerned spend the 20 bucks and get a new one.
If there is no cracking on the hitch head, they are pretty indestructable. On further thought I would get a new ball just for safety. I can think of a couple of stories where the shank failed with no warning.
Wire brush the whole thing and put a frsh coat of rustolem and you will be set.
WBCCI #5501 AIR # 49
1978 Argosy 28 foot Motorhome
Wise men talk because they have something to say; fools, because they have to say something. -- Plato