"Kimberly Kay" resting on a chair w/ some stomp pedals on the floor
A 1960s-era Kimberly Bison guitar that Billy bought for $60 from a pawn shop in Madison, WI. This guitar was used for the howling feedback in "Mayonaise", and on "1979". Billy has nicknamed it "Kimberly Kay". It made an appearance on Kerry Brown's blog in Sept. 2009, including a brief video of riffs from "Astral Planes" through a Binson Echorec, and again in June 2011, when it was used to record Oceania track "Panopticon".
The one that Billy uses has had the knobs replaced with Stratocaster-style knobs, and the tremolo arm is missing.