I too own a meteor shower 1958. Responding to some of your questions below, but my only "must-do modification" would be getting your tires up to at least the OE size that is consistent with your speedometer and odometer (265/70 R18). How anyone lives with a configuration that overreports mileage and speed is foreign to me.
- If there is a self-healiing property to the clearcoat (outside of science and the coat being a liquid substance in a solid form, subject to hot and cold conditions mimicing that effect) my LC missed that appication.
- I have been using the Armor All matte cleaning wipes on all hard plastics for the past decade without issue (interior and exterior). For exterior, I spray the vehicle down with just water, use those wipes on the hard plastics, then proceed with a normal hand wash. They come out looking new without residue or shininess. Then again, I am not bothered by those bits getting some wear and tear as they are intended.
- The interior fabric is phenomenal IRT durability and stain resistance. I haven't had to do anything but vacuum and use plain old warm water for all of the messes my 11, 7 and 5 year olds have cooked up. I did cage the cargo area to keep my malinois from tearing up the seats, but have since have allowed him to join me up front without any visible damage.