I have a spare bach 36 bell (no neck pipe) and a tuning slide that I had planned to add a valve to, but I never got round to it. The bell section has some threads on it, but it doesn't fit anything I have, so I'm not sure what they are from.

$500 plus shipping for both.

https://photos.app.goo.gl/L5NFxu6vVa8z4HF68