To late. Everything is back together.
Yeah. That's the way it works. At least, no issues.
I think it took me 2 hours to take out the wheel well covers, remove the bumper cover, remove the tail lights, remove the bumper and the crate and those brackets, grind off a few bolts, etc.
While it was apart, I got brand new bolts, and had them coated. I stripped the solder joint, removing all the old solder and electrical tape, then carefully re-soldered and covered with heat-shrink tubing. I put it back so that it isn't under pressure. I also fixed the ground in the right rear wheel well, while everything was apart. I cut the bad parts out of the steel bumper, and welded in a plate, then ground it to match the rest of the bumper. I painted the bumper with primer, then coated it with truck bed liner, basically submerging the bumper in it to get the inside of the bumper.
While the cover was off, I scraped the frame, treated for rust, sprayed with primer, then coated with truck bed liner. Rather than use the damaged egg crate, I used that stuff from the Saturn bumper that looks like styrofoam. I cleaned the inside of the bumper cover thoroughly, and cleaned the sockets where the tail lights sit. I removed the reflectors from the bumper cover and restored the reflectors with toothpaste. I removed the exhaust shields from the bumper cover, and spent hours polishing them, then jet-coated them. I restored those nuts or whatever for the tail light screws and had them powder-coated, then cleaned the tail light housings. I treated the tail light screws for rust, then had them powder-coated. I put some of that coating to keep bolts from seizing on them. Probably accomplished nothing. I also changed the heads of the screws from Phillips to hex. I wasn't happy with the tail light housing restoration, but it is unlikely anyone would usually see that. I replaced the bumper cover fasteners.
While the wheel well covers were off, I cleaned them and restored them. Not my brightest idea, but I cut out the rust in the wheel well area, welded plates in, ground everything smooth, treated for rust, coated with primer, then fiberglassed over that, then painted with truck bed liner. I went a bit light on the fiberglass hardener, so the fiberglass isn't rock hard, but I would do it differently, now. I replaced all the wheel well fasteners. It looked beautiful, even 2 years later when I sold that Fiero.