He did play there... But not anymore. Butch has played so many places it's crazy, he moves around a lot in St. Louis. The one place you can find him for sure is musicians events, like the ones that are usually organized by Greg Haynes. But yeah, he's always been a mysterious cat and I think he likes it that way. Seems to enjoy showing up out of nowhere to surprise everybody and killing it on the organ and then disappearing until he pops in again the next time.
If you really want to contact him though, I can probably put you in touch. Keep in mind though that he usually stays away from the limelight instead of trying to call national attention to himself. I think he would actually be pretty unhappy with the way people are hyping him up on this forum and comparing him to everybody else.
Oh yeah and, I know you've already heard this from a bunch of other people but, I'll say it too; I'm not even living in St. Louis right now, but I can still say hands down that, out of all the organists I've heard in all the different cities, and everything I've ever seen or heard on the internet or on recording (and I have seen some SICK stuff), Butch is still the best I've heard. Ever. Hands down.