I used POR15 chassiscoat black, dont know if its concours correct but it looks really good. It's a nice smooth shine not too shiny not too dull. Sorry dont have any pics posted yet of how it looks, but I think it looks great, Good Luck..
We do disagree from time to time and he still does not believe me about what the letters and digits of a part number represent!!
I believe I recommended DP90LF with 402LF catalyst and a DT reducer (number code depends on humidity) mixed at 2:1:0.5. The slower catalyst allows the paint to set up smoother and the reducer flows the paint better creating a better semi-gloss appearance. I don't think the color is gray in anyway, but I do agree with Charles that the original black is a blacker black, if that is possible.