...and the "MP" stands for microprocessor -- the "Super-7" design was intended as a low-cost rebuild, and did not originally include the sort of microprocessor control of the Dash-8 line (though the wheel-slip control system, "Micro-Sentry," did incorporate a microchip). NdeM was the only large-scale custome, rebuildin a lot of their U30C, U36C, and some C30-7 (or (C36-7) into C30 super 7. They liked them enough to order new units (i.e. built on new frames) to the same design, and asked for an upgrade: their final order came with the microprocessor control.
Visually they look more like "Classic" C40-8 (or C39-8E: narrow nose with sharp corners as opposed to traditional GE "pug" nose, GE's version of a "Spartan" cab, angular radiator wingspan) than a C30-7, though there are detail spotting differrences.