Looks like a 5300/190 to me, complete with borked hinge...Looking at the speakers mounted behind the display, I'm guessing that that one would be a Hooper (3400) or Kanga G3 prototype.
Wouldn't mind having a look at that schematic, actually. PM sent.Back a couple pages. If anyone wants a q51 schematic, let me know. I have the full one on PDF.