I had the time to test the NOS Empire diamonds, they had been well stored and the suspensions remained supple like when they were new, and they are far better than the diamonds on the second-hand market, even the Tonar 667-DE which are good, are greatly surpassed by the quality of the NOS. Furthermore, I notice no difference between the E II diamonds and the E III diamonds, proof that they were cut in the same way, the only difference was the color of the plastic. As I explained earlier, Pfanstiehl had listed them the same and only the color differentiated them for ordering. And even, assuming there could be a difference, it would be minimal and not distinguishable by ear without specific equipment. So indeed, if there is a way to have a worn or damaged diamond repaired, it's worth doing it!