THANKS!!!There were, I believe, three runs of the gun made. Most people say the 1st generation were the best, assembled soup to nuts by a single fitter in the custom shop. They were carbon steel, Royal Blue, and if the fitter didn't like the finish, they were sent back to be nickeled. Stainless was introduced in the 2nd generation. I personally would steer clear of 2nd or 3rd, but a 1st in blue, 99% condition, costs about $1800. Worth the money, IMHO.
List of serial numbers by year of manufacture available at: http://en.wikipedia.org/wiki/Colt_Python