Really don't mean to necro this thread, but I found one of these today. Mine was already opened, so the paper seal was broken. The bottle seal seems really tight, though, so I want to naturally carbonate some beer in the thing. Objections?
I bought a couple for $1.75 each from CHI Company when I placed a larger order for quick disconnects.
http://www.chicompany.net/squeeze-sample-valve-head-24.html
Thanks for the tips!
I found a couple of Cornelius kegs at the Alamo thrift store in Pasadena, so I was looking for the cheapest way to make them useful. :)