The bottom of the studio Raider is very asymmetrical, and i believe that all screen used raider were also castings, which can add to the distortions between any model seen on screen. Both of the intake tube things had some differences in the angle and way that they interacted with the "floor" of the Raider. To add to the mess, one side where the wings attach was flat, and one was curved. The best way i can describe the way the bottom looked was as if someone held a piece of styrene in place by pushing down on it while gluing it to the top half of the Raider when they were making the production pattern.
The top, including the wings, was for all purposes cut from either a 36 inch hemisphere, or from a piece of styrene pulled over a 36 inch hemisphere, at least as far as i can tell. I did talk with Lorne Peterson about it when i saw him at Wonderfest a few years ago and has some recollection of doing it that way. When i was making the pattern for the V2 (which pretty much became this moebius kit) I had access to a production casting and was able to determine the diameter by tracing the curvature of the casting, then repeating the pattern until i got to the half circle point, and it came out to 36 inches.
So as far as i can tell, at least the intention of the angle of the wings would be to continue that same degree of curvature across them, but that does not mean that any production model was able to achieve or maintain that for filming, these things got knocked around a lot, I would bet that wings were either knocked loose and re glued or maybe not entirely the "correct" angle to begin with. I bet they never imagined that people would be examining these things so closely almost 40 years later....
