The bass is a three-quarter-scale instrument custom-made by California-based luthier Mark Garza with a Rickenbacker-style body and Telecaster-style headstock with the name “Garz” on it; according to Kira there is also a small nick in the headstock. It is the only model of its kind in existence; it has been Roessler’s main instrument for the past several years.
Hopefully, the uniqueness of this instrument will aid in identifying it if it turns up somewhere, and the odds of its return to Roessler are greater. If any Boing Boing readers happen to see it or have any leads, they’re welcome in the comments.