I was rather intrigued when I saw this question, I did not realize that they still refered to "Brewster Green" as an automotive color this far removed. Brewster was a carriage manufacturer, and of course thier "Brewster Green" was their own color, vastly copied. Today Carriage restorers (yes, this is a large ongoing industry)still use the Brewster green color. I know one place that sells paint for carriages, but also for metal applications, is Schwartz Mfg. in Berne,IN. 574 - 642 - 1257. You will probably need to leave a message, but they will get back with you. I have not used it, but they have been around for awhile. They may have a better color match to what you want.