Some of the hardest-to-repair rust in the car was in the door pillar areas (as demonstrated in this previous photo).

I wasn't able to find any NOS replacement panels so Greg searched until he found a rust-free 1966 donor car (from an AZ junkyard).

As you can see from the oval hole in the dash and the fender emblem, this car was originally a Monza comvertible equipped with air conditioning.