If you wanted to prove it's provenience and are will to pay for it, you can go to Smith & Wesson's site and fill out a form and send it in with a check and they will give you back a certified letter that is kinda like the revolvers birth certificate.
You can usually get that cost back when you sell it as you state that it comes with papers.
I have asked the question directly by emailing them in the past, but that was years ago and I'm not sure they have kept up that level of customer support. Worth a try. They told me month, year, and how many were ever made of that model/configuration.
Otherwise, go to Smith & Wesson Forum Join and ask there. Lots of those guys have all the books and you will probably get two valid answers within days.