I had not heard about the early Ford metal finish process, John. It kind of explains why you could order any color Ford you wanted as long as it was black .

Here is some information on it from cranialstorage.com:

5) Ford

Ford used two japan black paints. The “First Coat Black Elastic Japan” was given the factory specification number F-101 (M-101 after March 15, 1922) and F-102 (M-102 after March 15, 1922) was the factory specification number for “Finish Coat Elastic Black Japan”. Both paints were very similar in composition. They consisted of about 10% linseed oil and dryers (lead and iron dryers were popular in oven baked paints), 55% thinners (mineral spirits or petroleum naphtha), and 25 - 35% Asphaltum. F-101 also contained 1 - 3% carbon black as a pigment, while the finish coat, F-102 contained none.

The surprising and interesting element in these paints is the asphaltum or asphalt. Asphalts are dark film-forming compounds that were used in paints noted for their resistance to water and dampness. The Ford material specification sheets usually specify that the asphalt used was Gilsonite. This is a natural, hard, brittle resin that is mined in the western United States as well in other places around the world. It was used in the manufacture of many products during the 1920's including paints, varnishes, oils, and shellacs. When compounded with other asphalts and rubber it was made into automobile tires, phonograph records, waterproofing and insulating materials. When used in paints Gilsonite must be melted at 270 - 400 degrees before it is added to the linseed oil and dryers. As a part of the paint, the Gilsonite is low in cost, acts as a hardening agent for the oils, and results in a high-gloss dark-colored surface. It also tends to increase the plasticity of the paint, making it less brittle, more flexible and able to withstand the vibration of fenders, hoods and shields without cracking or pealing.