To the best of my knowledge, this body shape belongs either to a Kramer the Duke, or to a Hondo Alien (I have one of each, as it happens). The sharp corners on the neck end plate make me think it's a Duke; IIRC the Aliens had rounded corners (just as well, the thing is lethal). Also the Alien was labelled on the front.
I don't think it has anything to do with Steinberger.
http://www.ebay.co.uk/itm/Used-Steinberger-Style-Headless-Electric-Bass-Guitar-in-Black-/291658752330?hash=item43e837614a:g:8sgAAOSwHaBWlZDQ