Where to find rear door panels and middle row seat foam?

[FLYNAVY30]

I'm doing some interior work in my truck ('72), and all 4 interior door panels are shot...cracked, brittle, faded, etc. Obviously the fronts are easy to find, but does anyone have a source for the third door and the opposite interior panel?

Additionally, does anyone have a source for middle row bench seat foam? I have the bigger middle bench as my truck did not come with a 3rd row.

Thanks for the help!

-Greg