It really depends on how perfect he wants it. The drip lines are leaking those cost nothing and only take a few minutes to change, it would be silly not to replace them.
But the pre chamber leak could go on forever and not affect anything.
The pre chambers are probably worn, I bet the balls are moving around in them. And their is no such thing as a perfect set of 30 year old injectors.
So if he bought four new pre chambers plus seal rings and got the injectors checked and rebuilt that would certianly be the anal extreme.
However the car would probably run a bit better.