I was once told that the AAR/TAs wear painted flat black/organisol on the underside above the mufflers. I have been told on here that that is wrong. I sure would like to have seen pics and have it documented, but I guess you said its gone now. Anyway common beliefis that the entire underside was gray primer with only body colored over spray as you would expect from halfass painting the rocker panels and engine compartment. Maybe someone else can chime in, I know Troy has done extensive documentation on the T/A he built.