Chevyguydan,
The first place I would try is a GOOD auto paint supply house. Most of the paint books have a section in the back that list fleet colors. The one piece of advice I would give you is, Keep Trying. The old paint code books are like gold, and in most cases locked in some back room. I went looking last week and it took some talking before one of the old timers brought out the old books. The young kids didn't even know they had them in the back. Try several stores and try again.
Good luck,
Ed