Most of my hearing was left on the beer stained carpet in Perq's in Huntington Beach, CA. As I recall, the damage was caused by Walter's 70's strat that was white when I first saw it but is now the one he's most known for, and a Mesa Mk IV sitting atop a Mesa 4X12 (I think it's a 4-12).
I don't know how much Walter may have strayed from that setup but no matter what he may have switched out he'd get "his sound" with that rig. Don't recall if there were pedals on the floor, if there were, it was maybe one or two tops back then.
There is a DVD of Walter live at The Paradisio and there is a section where he covers his gear. That's about 5 or 6 years old at least now, but I think he was still using that stuff then.
EDIT: I'm pretty sure the gear mentioned above would have been what he was using on Live Trout.