Kudos to Aaron Beck Brass Works! I bought a $50 vintage Boehm Meinl off of Ebay and discovered that it had a mismatched valve cap on the third valve. Said valve cap clattered every time I used third valve, which was uncool. Ever try to find a valve cap for a 70s vintage Boehm Meinl?? Anyway, I got a message from Aaron after posting my tale of woe here, and he offered to machine up a new valve cap. Shazaam! I got the horn back today and it's perfect. The only clue that the cap is new is that it's shinier than it's compadres. Pictures are posted here: Pictures by prstorms - Photobucket. I can't say enough good things about Aaron. His workmanship was spectacular, he kept me informed every step of the way, and his prices were way fair. I might just go break something just to give him another project. Okay, maybe not. If you need an obscure part machined, and you have a copy of what you're looking to replace, Aaron's your man!