I went to a local auto paint supplier and asked them if they could get '50 chev mariner blue. The counterperson was kinda shocked when she looked it up on her computer and was it not only there, it was offered in almost every line they carried and in enamel, bc/cc and urethane single stage. Recognize that the vendors are generally selling enamel, which although is period correct, it is yesterday's technology. I purchased the Dupont urethane single stage. It was expensive, but sprayed nice and looks period correct. Later when a purchased some more, I found out the same color is also known as "Canadian Railroad Blue". I found this out when a can had this on it and they told me it is the same color.
