Hi Nils,
According to Randy's site, the kit is about 37.5" (95 cm) long... and assuming Imperial Star Destroyers are "one mile long" (popular specification), it would be 1/1680 scale then.
But that is the thing with filming miniatures - they are not necessarily built to scale (hence the problem to define "Studio Scale") - they just have to work on screen, not in reality.
The original ISD has a forced perspective built into it for example, the lateral trench in wider at the front. And the other large model (more than twice as long, made for Empire) has completely different proportions and details - but it has still been used to represent exactly the same ship (please spare me fanboy explanations like "Victory classes" and whatnot). Another fact is the ILM model makers had the 1/350 scale in mind when they worked on the original 4 ft. miniature for Star Wars, making the entire "what's the scale" discussion even more ludicrous...
Cheers,
Falk
