Parts interchangeability(is that a word?)

[Good for nothing]

So I know my Cadillacs, but I'm new to coaches. I have a few questions about how interchangeable some body parts are.
For example, Could the rear doors from any '81 brougham fit on my '81 superior?
And, I know the door panels wouldn't be as fancy, and wouldn't have the same controls, but would they be compatible as well?
And the dash? I'm almost convinced it would fit no problem.
Just trying to figure out if it would be worth the trip to a junkyard, or if i should just fab it... I'd just like to be able to roll down the back windows as well(and if i'm replacing the back doors, might as well suicide them)
Thanks in advance.

[EternalCombustion]

I'm afraid you are out of luck on the doors. Your car is most assuredly a commercial chassis car. This means that cadillac sold your car to the coach companies with basically the front clip including the dash but frame rails and the rest of the running gear from there back. To find doors you would not only have to get coach doors, but you would have to get doors from the same coach maker. The dash however, should be standard cadillac.

[Good for nothing]

OK, Thanks! I figured it was mostly custom built. I knew they were relatively stripped down, but not to that extent! Means the interior door panels on the front are different too, yeah? Should be fun to track some of those down, lol.
Oh well, guess I can still replace the dash and suicide the back doors i do have....

[mr x]

Your rear bumper ends on that year should be the same as a standerd cad tho. I junckt a 84 hearse a couple years ago. I saved the fenders, nose , front bumper as well as the rear tail lights and bumper ends for my friends 80 sedan devil. The parts were not perfect match, but they workt well enough. You might be able to get away with a standerd gas tank as well.

[Good for nothing]

Ah... also good to know! @ least I can get some parts from a junkyard. Kinda bummed about the door panels though-the driver side one doesn't have the gasket to hold the window in place, so it rattles if it's down. I'm trying to see just how easy it's going to be to restore. I've done restorations from worse condition, but parts were easier to find.

[EternalCombustion]

Another good thing to know is coach companies didn't spend a lot of money reinventing the wheel. With a little detective work you can find things like weatherstripping and window felts. I replaced the window channel felts on my S&S here http://www.steelerubber.com/. I also got the weatherstripping from them also, thier catalog has nice side section pictures to make it fairly easy to match up weatherstripping.

Another example of how they reuse existing parts. The rear interior lights in my S&S are dome lights out of 68 and up El Caminos. So, there are ways of getting some of the things you need.

[Good for nothing]

Killer resource! Thanks for the link-now the carpet won't get soaked after a rain!
Interesting way of saving cost on the coachbuilders part, too...
Again I definitely appreciate it. I swear, someone should start a procar junkyard.