Per Hatcher, the original finish was "a mixture of flat black paint and synthetic enamel thnner to the ratio of two ounces of thinner to one quart of paint. After the paint is applied it is baked on at a temperature of from 300 to 350 degrees F."

He states that the finish was not very satisfactory and soon wore off. Later chemical finishes were more durable.

I have used flat black barbeque grill spray paint with good results; it is very durable, as is flat black engine paint.

Jim