[Jordan Baker]

Great looking project you friend has. I wish mine had had that much front armour on it when I got it.

To answer your question about the "grinding" marks. These were the result of a machine hammering flat the armour plate. Due to the process of making armour plate at the time you would get some distortions in the metal. This machine would basicaly pound it flat again. Thats why you find the marks in some areas and not others. Somtimes it is a few marks and other areas hve lots.

Im sure someone here could better describe the method using the correct terms and all.