In recent years, most body shops of any size, have gone to mixing their own paint. That way they don't have to buy so much paint and they can adjust the shades to match faded paint. You could probably find one of these that could mix what you need, but they probably won't have the old codes. Most however, can match the paint with electronic scanners, but remember that the paints of today aren't anything like what our trucks had on them.
