I had a vintage paint chip sheet from just about every company when I was trying to match my "54 Aero color. Most of those companies are long gone or absorbed into others. The only one useable to anyone was the Ditzler (pittsburg plate glass) sheet, still in business as PPG. You can probably find one on ebay.
You may ,like me, run into your supplier only having modern metallic particles, brighter than what was in vintage paint.
If you want that subtle vintage metallic, I highly recommend these guys.They stock it and can mix your color in enamel, acrylic, base clear or lacquer.
http://www.autocolorlibrary.com/