Reminds me when I bought my AMX. The underside was reasonable, just typical rust holes at the sump at the rear mounting points for the seats. Then I took the car home and started working on it, starting by striping the interior. Under the carpet was a 1/2" coating of roofing tar! Yea, that was one fine mess to clean up! After that, I haven't been to motivated to do the underside.
Man, I thought Dwight was a 4-speed guy forever. F/SA Fairlane? Talk about moving to the dark side!
Just in case I get motivated (or bored) I'd like info on this tool that was mentioned.