I am updating my engine compartment and would like to keep the factory firewall markings. I have a (B) that is underscored in orange, a white (X) and the number (52) not sure what the color of the number is. I am assuming the 52 is for my paint code Crimson. This car was a n early January Fremont car. Any idea what paint they used for these markings? It had to have been thick because even with my spray can coats of paint with an ultra violet light I can see these markings. I also went over the firewall with steel wool prior to paint. Maybe it was an oil based paint used to mark the firewall? I'm painting the engine the correct bronze color, was the dip stick tube painted engine color?
Thanks!

 

My 69 Cutlass S firewall is loaded with those dimples and globs of what appears to be some kind of sealant. They really didn't seem tp pay too much attention to how those firewalls looked out of the factory. The assembly line markings are cool.

 

The dimples are locations for holes to be drilled to accommodate mounting optional equipment.

 

Thanks at first I thought they were dings from when the engine was swapped out

 

You're close. The firewall and frame marks on my 1970 Lansing car were made with grease pencil. It's oil-based and surprisingly durable.

The engine was assembled when it was painted so that paint wouldn't get into unintended areas. Masks were used to cover areas that were to remain unpainted for cosmetic reasons (such as an aluminum intake on later years). Therefore, your dip stick tube would have been painted.