In checking further, I find that you are correct about the exhaust system being a Mindtrain system; I bought the car in 1979 from the first owner and at the time paid little attention to what I bought, I was so overwhelmed by having a Pantera. Later someone must have told me it was a Hall system, so I never questioned it. Yes, the exhaust has a bit of a crackle to it, but I see from an older post that a crossover pipe can solve that.
That may have some advantages, but I don't like the appearance.
I learn a lot from you all.