Hi Ray! Welcome to the forum from Texas. I'm certainly not an expert and someone may come along to correct me. But, I'll try to help.
If your gun came with a fired cartridge case, the envelope it came in is dated when the cartridge was collected. The box end label is marked with a Julian date (example 0212 is the 212th day of 2000). These 2 dates are usually no more than 2 days apart indicating when a handgun was completed and ready for shipping.
I'm not sure it would offer you any other important info, but here is a link to the SWHF website that offers instructions for getting a letter on your gun.
Smith & Wesson Historical Foundation - Home Page - Insuring that the rich history of Smith & Wesson will continue for generations to come Letters are on a bit of a delay (maybe 10-12 weeks) for the US.
You can also post any questions you have in the section of the forum related to your revolver. People who are knowledgeable about that model can maybe answer more questions you have. Someone there would probably help you decipher the date on the box.
Hope that helps!
Lynn