TromboneChat

I have a mouthpiece that I (or someone family/teacher) ordered for me in the late 1980s. I think I was previously playing on a Schilke 51 with a Conn/long shank and got this when I started playing a Bach 42. Does anyone know if the “S” stamped on the side might mean “short”? Interestingly, I think it has a slightly Shallower cup and an extra Sharp inner rim. I bet I knew at the time but I’m contemplating lots of uses for the “S”. In addition to the rim in the pic, I have a 51N (narrow rim) also made by Scott Laskey. Anyway, I’ve been spending a bit of time with this MP and wonder. Got any ideas? The “Allen” stamped is my name

Thanks in advance for any help!

Maybe it means standard shank? That does look pretty short, though.

Thanks! I just don’t remember seeing that on other standard shank Schilkes.