I have lost a part to my Holton Galaxy b-flat. Can't remember part name but it's a long silver stud, threaded at one end, that keeps the third valve slide from sliding out too far. I'd also like to know where to find that part. Thanks.

I don't know the part's name but you seem to need a stainless steel screw or a piece of SS studding with the right diameter plus the right thread.If you get stuck for finding the name you might consider using this instead.