The door fit right now is of little consequence. Getting the gap fairly even when you do the repairs is what counts. Chances are sloppy hinges could be contributing... the driver side is usually bad from more use.
You'll know a lot more once you get it cleaned out and start taking it apart. Pull the hood, front fenders and related sheetmetal and the make a thorough assessment of the cab damage. A good pressure washing is in order.
As mentioned previously, if the floor aft of the front of the seat riser is good, you'll be better off just replacing the front part. Just remember that the more stuff you cut out, the more problems you can create.
I appreciate the offer of the door art... the collection is growing and every day another is lost.
