Richard: Mouthpiece recommendations are almost useless, that's why I hesitated before even mentioning the SS-J. I did so only because others here have posted in the past that when they moved up to the J, it was better than the smaller tip-openings.
I use the SS-J on my '28 Buescher TT and believe me, I've tried a lot of soprano pieces. I once had an SS-I and did not like it. My adult daughter loves it on her YSS62S.
I recently tried a Buescher soprano mouthpiece opened to .070" by a SOTW poster. I did not like it any better than other stock Buescher mouthpieces I'd tried.
One person's bright is another person's dark, though. There is no accounting for how one reacts to a mouthpiece (or a saxophone for that matter).
Another piece that I liked on my TT (and use on my modern sops) is the Morgan Vintage (I use a #7 on my S992, a #6 on my curved SC902).
I agree about the harshness of STM Links, although a world-class player I know and play with sometimes use a Link8* on his MKVI soprano and sounds wonderful. Of course he'd sound good on anything, I believe.
I have STM Links in 7* and 8*, and traded away a 6* a while back. I tried to use the Links in public performances - they projected alright, but were harsh.
Hope this helps. DAVE