There are many here that have the opinion that the most dynamic way to really bring out the potential of a high-end older frame is to run it on modern wheels.

I share that opinion. For me, that includes not only lightweight racing wheels, but also high-end lightweight all-around wheels.

Noticeable, attention-getting improvement in almost every case.

I also agree with der Kommisar that they don't have to be that modern. I built a set of DA7400 hubs onto Wolber Super Champion Alpin rims, with DT Swiss spokes, and when they were properly tensioned and trued, yielded a most outstanding ride.

If you truly don't want to change wheels, though, getting them trued and tensioned to a gnat's hair of perfect will yield a significant change, too.