slippery cars
As for lowering the car on the suspension, this requires using shorter and stiffer coil springs in the front and lowering blocks between the leaf springs and rear axle, if your vehicle has leaf springs in the rear. If its got coil spring rear, then using stiffer shorter coil springs apply to the rear as well. This is not something that you will just walk in and find parts on a shelf. Using shorter coil springs with stiffer spring rates requires knowing your vehicles weight at each corner, and knowing the suspension geometry as well.
Linconln and Cadillac both had variable suspensions for a few years, but I believe the cost was too great for the demand and they stopped production of such units.
As for doing back roads, if you are going to lower a vehicle for aerodynamics and for handling, you will just have to take your chances on the chuck holes etc on gravel roads.
The chrome can be kept but the idea of removing it was to minimize the turbulance it causes, no matter how slight. when you shave off the door handles, this requires using electric celinoids to open the door latches or else leave your windows down all the time.
As for the hood, that was LOUVERING, not lowering, the hood at the rear.
Louvers are a small slot cut in the sheetmetal and are formed with an anvel that fits near the slot. What they look like is a very small hood scoop, about 1 inch tall and usually 2-3 inches wide. The opening would be facing to the rear, toward the windshield. Having several louvers across the rear of the hood, just ahead of the fire wall a few inches will allow the hot air buildup under the hood to escape, allowing more cool air to enter and cool the radiator. This will also, due to the air flow coming out from the louvers, reduce a hi pressure point at the base of the windshield, which is an air flow restriction. Again this gets into a topic called laminar air flow and I dont really understand it all, but do know it works.
Im not sure what you are referring to by bullit style headlights.
As for the golf ball effect, and the idea of using sand paper, which the texturing would have a similar effect, up until the late 70's, early 80's, most super speedway cars were running matte or flat finish paints just for that effect. I dont recall the exact year but it was probably when Winston took over the Nascar Grand National Class, that the idea of shiny paint jobs became somewhat mandatory. Gotta look pretty for the grandstands and the advertizing.
You will notice that when the NASCAR and other sanction teams go to Daytona prior to the opening of the season, to do test and tuning, vertually all of the cars are still in primer, which is a flat finish paint, and here again we get back to that laminar air flow thingy.
Spoilers on 50's and 60's cars.
The only reason they put those fins on cars in the first place was to give them a supersonic jet aircraft appearance, a theme which was followed through on both the windshield and rear glasss of most of the hardtop vehicles of the time, As well as how instruments were clustered in the dash. The idea was to give the illusion of speed, as though one was flying his own Jet Fighter plane. If you look very carefully at pictures of the aircraft built during the 50's and 60's, then study the styling of most of the major auto manufacturers of the time, you will see a lot of styling cues were taken from aircraft, IE bullets in the grill to represent the intakes of jet turbine engines (49-55 Fords, particularly). Markers on top of the front fenders and hood ornaments that vaguely resemble gun sights, tail lights that look like the exhaust on a jet engine.
The one inherent thing putting fins on some cars did was give them some straight line stability at higher speeds, mearly by accident, Im quite sure.
These fins would have little effect on a spoiler, unless you are dealing with something like a 59-60 Chevy, which the fins did have a tendency to make a car light in the rear at high speeds, in which case, the fins would be fighting with the spoiler for air flow supremacy. A vehicle with fins that run straight up and down may help in creating a minor channeling effect of the air to assist directing it over the spoiler.