Thank you all for your responses and recommendations.
Redglobe, I agree with your assessment regarding the causes of sibilance. I have tweaked, and tweaked, and tweaked. One day (it's amazing how the ah ha moment in life can take some time), I threw in a CD in my Arcam CD-player and confirmed that it's not the TT, but it still could be the room, the stuff in the room, the speakers, the pre-amp (old Mac C32), or one of many other factors, but I don't think it's the TT. My dealer and I have an excellent relationship where he will allow me to try a few carts out prior to purchasing. I'm going to take each of your recommendations and try a few. I'll post my decision when it is make. Thank you all again!