There are still many things to be done, but I think I'm in a position to avoid embarrassing myself. The good news is that no one expects everything to be working, so the fact that -- to use an analogy -- the engine starts and the car rolls down the road under its own power should be sufficient, even if it really needs some body work and a new paint job. :)
Update: And the demo has been postponed until Monday, so maybe I've got time for that paint job...