I've got a Bach Stradivarious Model 37. The third-valve slide doesn't have a spit valve, just the removable tube portion that you pull out to empty condensation. I recently had the horn cleaned, and now (for the first time since I've owned the horn) the removable tube frequently pops out an inch or so when I'm playing. It's super annoying. Any suggestions? I was thinking of buying a replacement third-valve slide that doesn't have the removable tube and has a spit valve instead, but I'm having trouble finding any. Anyone know where I could get one? A used one would be preferrable. Those Bach replacement parts are silly expensive!