It sure make sense. Goodluck with it, and as you know, we like pictures.
Have you contacted Osborne reproduction? They have aslo books were you can find detailing engine bay etc.
I have an old mail here recieved 98 when i asked the same question. this was what they told me:
I was forwarded your E-Mail from Phil Parcells regarding your Undercarriage. The Floor Pans on these cars were originally painted with
either a Red Oxide, Gray, or Black Primer. When they painted the car, the
Body color was painted onto the underside of the Floor Pans. This was nothing more than overspray, when they painted the Rocker Panels and lower pinch weld. Next, on light colored cars, they painted this lower pinch weld Black, which now put Black overspray on top of the Body color overspray (not really a pretty sight). Next, they sprayed Sound Deadener (Undercoating) in the Driveshaft Tunnel, and on the bottom of the Floor Pans, stopping about 8 to 10 inches from the outside of the car. The Emergency Brake Cable was on the car when this was sprayed, which left a distinct line on the Floor Pan, where the Sound Deadener hit the Emergency Brake Cable and not the Floor Pan. Every car I have worked on has had varying amounts of overspray, Sound Deadener, etc., etc. It all depends on what day and shift the car was built. I hope this
gets you started.
This was what you wanted to know right?