BB, clearly you are in a unique situation but here is how it goes together for most. You get it to a rolling chassis, engine power train and all. In other words if you could find a way to sit behind the wheel, you could drive it. Then stating in the front with the grill, then fenders then tub and button up the rest.

An oversimplification but that is the way they went down the assembly line. I don't think you will be able to dial in the pedals and what not till you get the tub on. They have to be "adjusted" in a real one all the time to fit just right. Many don't realize the pedal arms are forged and they are malleable to some extent. Slight bending (or reprogramming in your case! ) to get a perfect fit is not uncommon.