Good point and correct, we are talking about cars important to us and not necessarily the collector car market but in the opinion of this life long car enthusiast and dealer here's the deal.
There is no adhesion quality like what the factory is capable of - their products will almost stick to air and spray boot enviroments are darn near sterile
There are products sprayed in Germany that the feds won't allow here
Something can be restored a hunderd times, but it's original only once
If a section or panel is refinished there can be matching issues and /or it will age / fade differentlly than its surroundings
Why was the section or panel refinished? Repair to just a small scratch or major damage? Is there exposed metal or rust that wasn't properly treated or corrected? Some one else may have opened their wallet for this repair, but if we own the car long term and it wasn't repaired correctly we may one day open even wider to correct!
As a dealer I (we) always devalue a car if it has been refinished. The more valuable or newer the car the more the devaluation. Our cars? Opinions vary. If the job is done correctly not so much. The longer a car is in service the more likely it will require repair or painting
So if you have an all original beautiful paint finish do your best to keep it that way
-vs-
A paint expert with tons of experience and talent can lay down a paint job that is mind blowing.
Today's repairs are done with products that far exceed the quality of years ago.
Today's products require training before application - once you just watched a guy paint then tried for yourself - trial and error training
There are obviously more cons than pros, but it boils down to this. IF you have to refinish anything on your love stay away from MOST production type body shops as they are forced by insurance companies into doing repairs as quickly as possible. Find yourself a custom shop and be prepared to come out of pocket more than the insurance estimate (if there is one involved) and describe in detail what you expect from them to include not only the quality of the finished product but what they can do to hide (from a trained eye) the fact that repair has been done.
I purchased my car with all original paint but horrible acid rain damage. I trailered it to the best buffing guy I know. You can still see pits in the clear, but it now looks almost new and I wouldn't repaint it if it was free.
Sorry for the novel - was hard to say in two sentences