I tried what you recommend and I believe you are right about them doing their research. In Westmont, Illinois we have Import Row. Mercedes, Porsche, Audi, BMW, Infinity, Lexus, Acura and Toyota are lined up one after the other. Directly behind them, is Westmont Body Werks. A huge facility. They do all the work for these local dealers. Got to take a tour once with the local Mercedes Club. They do impressive work. However, they are a collision shop. When I approached them about my car, they said thanks for stopping by but we can't help you. Collision work is different than restoration work. They are not into rust repair and fabrication. At least that was my experience with some of the local shops I visited. That is why I thought at a hot-rod shop, they will fabricate as needed and replace with parts when it makes sense. In my case, we bought a patch panel for the left rear quarter, the larger patch panel with the complete wheel arch for the right rear quarter and the small patch panel for the right side of the trunk. All bought from K&K and fit beautifully. Other areas that received attention were the frame below the battery, a small section of the passenger side floor, a small portion of the bottom of the rear panel below the tail light. The guys I use are able to shape and form metal. They even filled in the holes a previous owner made to install speakers in the rear soft top compartment panel and included the vertical depression.
Another thing I did that I did not mention previously, was to have the car media blasted prior to selecting the body shop. Ron at MediaTech in Naperville, Ill. was the right guy for the job. Here again I had talked to a few shops for this part of the process. Did you know that since we have aluminum and steel panels on our cars that they use different media? When I told one shop that my doors and hoods were aluminum, he said he would have to chemically strip those because his process would distort the metal. I did not use this shop but when the car came back from MediaTech, the aluminum parts were not primed like the steel was and still had some bondo. The body shop said they did the right thing and they would take it from there.
I can email the PDF (it is 9MB and too large to post here) of what I did to explain the process.
Media blasting revealed previous repairs that were poorly done by today's standards. Most competent shops no longer braze metal.
When I originally prepared my document, I included photos of my car as it was in its "as I bought it" painted state and did not look too bad from 5 feet away. After getting it back from MediaTech, I replaced those photos with photos of the real state of the car.
Again, it all depends what you are trying to achieve. I had several guys ask why I would bother to strip the car to bare metal. Answer: Because I need to know everything under the paint was done right.