Automotive Headlamp Reflectors
I bought the lampblack for a specific purpose, which worked quite well. When restoring antique automobiles, prior to the late 1940's there was a polished reflector behind the replaceable lamp inside the housing. You polish the reflector with a soft cloth and a mixture of lampblack and alcohol, moving from the center outward, not in a circular motion. This will restore the luster to the reflector and increase the efficiency of the lamp. Since most of these cars may not have had the headlamps restored for decades, it may or may not work in all applications. This is the procedure recommended by General Motors in their Cadillac shop manual; I would assume that other manufacturers of the period recommended a similar method.
Remember, many if not a majority of the servicemen who worked on these cars are not with us any longer, and there is a significant amount of knowledge to be found in service manuals and bulletins of the period.