I think your revolver is a Smith & Wesson .38 Single Action First or Second Model. This is my best guess.
You might be able to find info on the S&W Forum: http://smith-wessonforum.com/eve?cdra=Y&s=884106832
Here are the two standard reference books on Smith & Wesson:
History of Smith & Wesson, by Roy G. Jinks.
Standard Catalog of Smith & Wesson, by Jim Supica & Richard Nahas.
You might consider a factory verification letter from S&W. There is a fee for this.