[Too Many Projects]

There's more than just spraying from a gun on those cars. I see a lot of air brush and hand pin stripping too.
Lace is about the easiest, as you just pick the pattern you want and find a way to keep it tight to the panel. Then there is the Dart with a lot of taping and air brush for the shadow effect in the blocks.
One of the members on here did a lace job on the roof of his '55 and it is very well done and cool.

As for the paint, both lacquer and enamel were a gloss product and single stage urethane will be the same, no need for a clear over it all for gloss.