72 AMX Javelin Pre-Production Prototype

That's a good observation and a good point.  Although I'm completely unfamiliar with MIS and it has likely changed somewhat in the 50+ years since the photo was taken, it seems likely that MIS being a D-Shaped oval Speedway would have a retaining wall on a banked curve as well as around the entire track perimeter which is not evident in this photo.  So this photo was not likely taken at MIS.

It may have been taken at a road course like Road America since road courses often have run-off areas on mildly banked curves.

But a likely candidate for the location of this photo would be at the AMC Proving Grounds in Burlington, WI.  Chrysler sold the facility to MGA Research Corporation in 1988, who uses the proving grounds for automotive, motorcycle, rail, and aircraft industries testing.  Online views of the facility still shows (not sure of the age of the image) that the majority of the original paved surfaces are still there, though in poor condition from lack of maintenance over the years.  From what can be seen of overall and closer views of some of the curves, it appears that road surfaces are similar to the photo, and the photo could have been taken at the AMC Proving Grounds.  Two images below for your evaluation.