Mr. B is one of my favorite GN'R songs and it has a very unique intro, and from the album version it's almost hard to believe that it's a guitar. I notice that in the shows I have seen, Slash always plays the intro differently than the way you here it on the album. Do you think he fluked it or is it a very difficult sound to get live or does he just get board and decide to fuck with it? But every single live intro of Brownstone you see it is almost never the same twice.
While on the topic of Mr. Brownstone; I'm not sure if this has been posted before or this guy could even be a forum member but this guy Chris Buck is a pretty wicked guitar player and here is a video of him playing Brownstone:
http://www.youtube.com/watch?v=b9NIhdEQbWA