Hi! I do not know anything about your piano, but have some advice. If the treble is too high, and the rest of the piano is just plain too loud, you could get your piano "voiced" by a piano technician (not just a tuner). When they voice a piano, they use a little chemical solution on the wool part of each of the hammers, and pluck some of the wool to make it a little more loose with a special tool. When I was helping my grandmother pick out a piano, we found one that we liked, but it was just too high pitched. There was an identical one right next to it that was voiced differently, but was already sold. We tried the piano that was sold, and loved the way it sounded, so we had the unsold piano voiced exactly like the one that was sold, and my grandmother loves it now! Voicing will not only take care of that shrieking treble, but will also make the piano not as loud, becuase the wool will not be as hard on the hammers. Hope this helps!