For the flooring I've pretty much always been able to use the original or find one from a donor car. Plenty of owners, when doing new carpet are quick to get rid of the original in favor of some expensive fancy new wave stuff
For trunk I've always, when the car needs any, make my own using the same method shown in the article posted in the Library. Not sure if SnakeOyl is still selling the base material we used
As for the roof I use the same light weight fiberglass water heater insulation blanket, Guess I should by some extra with all the pressure of getting rid of gas water heaters in many regions of over all the states.
Just trip off the aluminum layer and a little insulation for thinner layer. Then spray both surfaces (roof and insulation) with a spray adhesive. Same stuff I use for headliner installation
Here are a few examples of originals. Not always in the best shape after all these years