Thanks for the comments. I agree about the engine nozzles. Looking at the model sitting atop the workbench at Mr. Bower's secret underground lair,the engines are clearly just sitting on the same surface. In the movie, the shuttle lands on this big elevated platform with extending blast shields that sort of unfold as it approaches. If you watch the landing sequence carefully (like I did when going for screen caps), you can see that the engine nozzles actually dip into notches or gaps in the platform, so that they don't come to rest on the ground. My take on the design of this shuttle also assumed that the extender arms holding the thrusters to the main body also had some positional "play" to them, like trim, that could raise or lower the engines up or down. I never saw any evidence for this, so feel free to disagree...I just got this from the look of the thing.