Hahahaha, the layer of paint is always a veil to hide the truth and past history of a car. But if we left the car in its original paint, assuming it is already over 30 years old, the paint probably looks terrible enough especially if the car is exposed to rain and sun light. I'm not including showroom or museum cars with original paint in this case.
So, a new paint is probably inevitable in order to protect the body of the car.
I admire those who refurbish the interior bits to factory specifications because it does look nice. What I hate is the refurbished interior which looked like square boxes taken out from racing cars. I've seen a few old school cars doing that with the interior. Random gauges and switches everywhere along with the box styled race car interior. I think the interior is important to remind you of what car you are in and driving. On old school cars, it gives out that nostalgic feel. But as for that race car inspired interior, I don't know what can I say about that.