It sounds like you've got a great start on it. That's fantastic that you can do some of the prepping and bodywork with your dad, too. That will save some serious money. I hear you as for being on a tight budget. The salvage yard you're working with seems to be pretty fair-pricewise. Hopefully, the door comes with the glass, too. I would imagine it would be easy to swap your current interior door skin onto the salvaged one.
Thanks for your comments on my '88. She's not without her flaws. Likewise, I have the sagging headliner, and found these headliner tacks in the automotive section at Wal-Mart that you can screw directly into the headliner to fix the sag. They are essentially the small furniture / armrest cover tacks that have a short corkscrew shaft with a clear head - but they are a little on the unsightly side. I've got the little blisters of rust around the door handles, and the passenger side rear door is starting at the bottom. Plus, my 307 goes through oil. All that, though, and the car still looks pretty good from about 15 feet away.
Does yours have the miles per gallon display next to the climate control? I always thought that was a great feature and wish they kept it for the '88. Do you also have the thermometer embedded in the driver's side mirror? That was a cool feature on some of the earlier Broughams, too.
Well, best of success with it. Keep us posted on your progress!