Believe it or not they didn’t spray paint carriages or early automobiles.
That was all done with a paint brush and usually Lacquer paint.
No, the early shiny smooth paint jobs weren’t done by a really brilliant painter, rather someone good at sanding ( which practically anyone can be)
paint brushes leave brush marks and sometimes runs or drips. But Lacquer dries so fast it’s easy to fix.
Why go backwards? Well cost for one reason. Lacquer paint is cheaper than 2 part paints. Plus you wouldn’t need to buy paint guns hoses, respirators, protective body suits, etc etc etc.
What’s wrong with doing this? Well, it’s not as fast on the production line. Over time, exposed to UV light Lacquer will fade and require buffing out. Plus you simply can’t get all the exotic fades and shimmers etc in Lacquer. On the other hand a nice hand rubbed Lacquer paint job has a depth and richness modern base coat, clear coats will never achieve.
Since these are special cars they won’t sit outside year around and if they must we tend to buy car covers for them. Nor is production speed important in a car that is taken apart, repaired and carefully reassembled.
Please don’t tell me all the horror stories. Most of them were by people who took short cuts or put on too many coats etc. there are Chinese artifacts going back hundreds years with smooth finishes still on them. My own MGTD has 45 years on it and is still presentable in spite of decades of neglect, racing and just driving. Or how tough modern 2 part paints are. They get scratched, dented, damaged, too.
The process is simple and I’m sure you can find plenty of U tube video’s that will show how it’s done. If not I’ll be happy to explain it