The R-Bi stamp indicates the revolver was sent from Customer Service to the factory (engraving shop for example) for the work to be done. The S followed by a diamond indicates a refinish in standard blue. The work was done in February 1978. Based on the photos and the location of the S&W logo, it is possible the engraving was done by Russ Smith, but recently, we found a factory engraved revolver (by Tom Freyburger if I remember correctly) with a similarly placed logo.

The stocks appear to be "customized" factory stocks that were done outside of S&W.

Since the work was done after the revolver shipped as a plain revolver (most likely), a factory letter will not reflect the engraving or other modifications since finding the actual work orders is nearly impossible. However, if you send a couple of good photos with the letter request, Mr. Jinks may offer an opinion about who engraved the revolver.

Bill