I have a bass like yours. I got it about 20 years ago from the original owner, who told me he bought it in the 70's in Los Angeles.
The neck comes out of the body. The man I got this from told me it came with a case that held the disassembled bass, but he no longer had it. Must have been a large case!
Our basses have the same shape and finish, but mine has a different tailpiece, no strip of wood across the back, and no knobs on the back - just a volume knob in the front.
I once saw a photo on the internet of one being played, but it had two or three knobs on the front. The only info I've found on this bass was in an early 90's Bass Player Magazine article on the history of EUBs.
I think its a good body design. The wide shoulders allow me to lean the bass against myself while playing and the small lower body keeps it portable. It puts out enough volume that I sometimes practice unamplified. Of course, it doesn't have the sound of a real DB, but it doesn't sound like a fretless BG. There is some DB quality in the tone. I had a bag made for it at an auto upholstery shop and its not much more trouble to carry than my Precision in its case.
My bass, the preamp that came with it, and a page from the Bass Player Magazine article:
