Ok. This is the final update. Instead of struggling getting the right sound with enough core frequencies and warmth and presence at the same time out of a Link NY which didn't have enough core frequencies, I ended up finding a Link STM 7* which is old and even has narrower ligature and may be even narrower body, but it gives warm sound including lots of core frequencies and I can easily manipulate the sound from dark to bright. It seals like no other Link I've seen before and although I was using 6 and jumping to 7* was a bit concerning, it seems I got good control right from start. Also the ligature fits like a glove, it has slightly bigger plate that sits well on the reed and I tried other ligatures (Rovner and Francois Louis) and non of them gave the same amount of projection and full frequency range. I ended up taking my YTS-61 and Link NY 6 mouthpiece to the only senior known sax repairman in Calgary, Alberta, Dave Edgar. He found a few more areas in the sax that was not fixed, plus tried the Link NY and found the flaws, and also showed me the old Link 7* which worked great.