Bob,
No clear coat over the paint? How did they protect the paint?
Paint at that time had allot of stuff/chemicals in it that allowed it to last decades not like the 80s-today with the peeling clear coats and such. The paint was allot tougher than the base products today. Allot of areas are limited to water base color layer
For the original paints waxes were added to improve and add a layer of protection
So when people are doing a concours restoration paint job, they are not shooting it with clear?
Many use single stage (paint only over the prep/foundation layers of primers and or sealers) just like originally done to reproduce the look and surface finish. Many of the cars you have surely seen at shows have been sanded and buffed to a mirror finish that some would consider "over restored"
Bottom side of the hood originally on a car like yours (and from the same production period) would have been a semi-gloss (on the lower gloss side) black with body color overspray along the edges and hood scoop opening as shown in a number of the unrestored threads here on the site