These cars were painted in lacquer; lacquer is not very 'shiny' before it's buffed.... If it isn't exterior surface sheet metal, then it wasn't buffed...
If you use basecoat/clearcoat, and put clear there, it will be shiny....... but I have no idea how the cars are 'judged', since most/all of the restored cars seem to have base/clear on them.... Isn't the 'wrong' paint judged down??