I did an article on the MPC 1971 SuperBird almost twenty years ago or so; I don't recall if it appeared in Scale Auto, Car Modeler, the Car Modeler annual, or elsewhere, although it was definitely in a Kalmbach pub of some sort.
In that article I referred to a detailed book that featured the Superbird and Daytona, and included some information on the stillborn 1971 versions. There was also, at one, time, a series of internet-based posts that showed actual photos of the scale wind tunnel models undergoing testing for the 1971 race season until NASCAR pulled the plug on all those aero cars.
My takeaway was that the MPC kit represented a pretty accurate replica of one of the actual 1971 versions, and probably was a very good forecast of how a real production line/for retail sale 1971 Superbird would have appeared.
If I run across the old article, I'll return here and post the info; if anyone else recalls the article and where it appeared, please post that info here.
Good luck with the project, it sounds pretty cool! TIM