From NASA Langley – they did wind tunnel tests on a model. Lots more pictures of various aerospace projects there too, some of them are quite weird. Thanks to Secret Projects forum for the info!
Naturally since Rockwell built the orbiter, this one looks like the orbiter too. With an SSME and RL-10:s (so Rand.org says) and cylindrical tanks, it would have been far lower risk than the Lockheed version that won.
In a sense, the “almost pure rocket” cone, the “flies a little better than a rock” lifting body and the “almost flies like a dangerous plane” winged vehicle are the three main paradigms to reusable vehicles.
Though, with SHARP (or like McD did with active cooling), your lifting body can be sharp edged and have vastly superior L/D compared to blunt ones.