Atlantic Carriage Works

In your other group of pictures (picture 2) divide the picture in four (upper left quarter) and close to the center of the whole photo there appears to be letters very faint "X C" cant make out the rest. Have you tried chalking the marks and burnishing it highlight them? Also I have used a light from the edge or side of the anvil to highlight the words on well marked up anvils. Not sure if this helps but good luck