There is a 1962 valvoline curb sign on ebay 181264255197. It is posted as a porcelain sign and it might very well be. I had one exactly like it. Made by the exact same company (A.M.) with the same model numbers and it was not porcelain. It had multiple coats of paint and a clear coat. Clearly a metal sign. In the last couple months i have seen a couple on ebay that were posted as metal and a couple as porcelain. One of the signs posted as porcelain definately wasnt. You could tell by the damage on the sign that it was paint. I would like to know if there was a porcelain model of that sign made or are the ones i have seen on ebay incorrectly posted. To be honest, with one that is NOS, being double-sided and having the thick layers of paint. I could see were someone who was kinda inexperienced could mistake a regular metal one for porcelain. Not sure if it always even makes a difference to some people or the over all value of the sign. But, i for one would be kinda mad if i bought a sign that was described as porcelain and turned out to be metal. I clearly dont know it all and im in no way an expert. Just curious what is really going on there. Personally, not a situation i have ever encountered before and im not sure what the truth is.