Here's what could serve as illustrated proof of a rudimentary early attempt at the craft of plumbing by "Joe the Plumber" (note unshaved dome).
Is it really Joe? Is he really a plumber?
Actually, this is a illustration I did a few years ago as part of a humorous product concept for my good friend and colleague Russ Schoen. Russ is a expert trainer, facilitator, and speaker in the field of creativity, innovation and leadership (though he probably couldn't help you with plumbing).
Pay him a visit at http://russchoen.com.
Image ©2006 Mindgarden Innovation Inc.