This strange monstrosity (built by Cigar Box Nation member, "Rooster") started off as a 2x4. I found plans for it inside an old 1961 Science and Mechanics magazine and posted them for free many years ago. Since then, several adventurous people have made 'em.
I'm reposting the plans in here for anyone who wants to try their hand at making their own 2 string electric bass. Let me know if you succeed!