This is really a very interesting rare instrument as well as beautiful and well preserved. This bass guitar is the prototype for the L6 S bass, a model that was never manufactured by Gibson. Although it is the prototype for an instrument that was not produced, it also seems to be a prototype of the Ripper and Grabber models introduced later that are constructed with the same materials (maple neck and body) and similar dimensions. The look of this one does foreshadow those later models. I thought I had seen everything until now.