As I have deduced over the years... The color dots were inventory codes from factory or distributor. The S on the frame indicates the gun was returned for service. Of course, the factory will go to all ends to make the gun right... the raw steel on end of barrel was from fitting the barrel cylinder gap. The special order numbers indicate the year (thinking 84) and the Julien date which appears to be the 109th day of 1984. It appears your barrel and cylinder have been replaced.