Hi there dombanzai. I'm friends with Alan Brackett and would be happy to ask him about this. He actually told me the story once years ago and I forget most of the details; but I do remember it was in the very early days of the BBs before Alan hooked up with John Merrill, so I'm assuming he was given a look on the drums prior to the time that Dennis decided he wanted to dedicate himself full time to the group.
That said, I would be happy to ask him and post his response if it's okay with him. Just let me know.
The Peanut Butter Conspiracy is a damn fantastic band by the way. Hugely underrated. I think a lot of people who are in to the Beach Boys would really dig them a lot. There's a big connection there as Gary Usher produced their first two albums. Anyone who is into folk-tinged psychedelic pop with ridiculously fine male/female harmony blends is highly advised to give them a try. This 2-fer CD is the gateway, though apparently pricy these days:
http://www.amazon.com/Is-Spreading-Peanut-Butter-Conspiracy/dp/B000040JF6